CA2820238A1 - Radiographic contrasting agents and radio-opaque polymeric materials for medical devices - Google Patents

Radiographic contrasting agents and radio-opaque polymeric materials for medical devices Download PDF

Info

Publication number
CA2820238A1
CA2820238A1 CA2820238A CA2820238A CA2820238A1 CA 2820238 A1 CA2820238 A1 CA 2820238A1 CA 2820238 A CA2820238 A CA 2820238A CA 2820238 A CA2820238 A CA 2820238A CA 2820238 A1 CA2820238 A1 CA 2820238A1
Authority
CA
Canada
Prior art keywords
radio
radiographic contrasting
halogen
radiographic
substituted
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA2820238A
Other languages
French (fr)
Other versions
CA2820238C (en
Inventor
Jonathan Z. Zhao
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cordis Corp
Original Assignee
Cordis Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cordis Corp filed Critical Cordis Corp
Publication of CA2820238A1 publication Critical patent/CA2820238A1/en
Application granted granted Critical
Publication of CA2820238C publication Critical patent/CA2820238C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00Preparations for testing in vivo
    • A61K49/04X-ray contrast preparations
    • A61K49/0433X-ray contrast preparations containing an organic halogenated X-ray contrast-enhancing agent
    • A61K49/0438Organic X-ray contrast-enhancing agent comprising an iodinated group or an iodine atom, e.g. iopamidol
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00Preparations for testing in vivo
    • A61K49/04X-ray contrast preparations
    • A61K49/0433X-ray contrast preparations containing an organic halogenated X-ray contrast-enhancing agent
    • A61K49/0442Polymeric X-ray contrast-enhancing agent comprising a halogenated group
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L17/00Materials for surgical sutures or for ligaturing blood vessels ; Materials for prostheses or catheters
    • A61L17/06At least partially resorbable materials
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L17/00Materials for surgical sutures or for ligaturing blood vessels ; Materials for prostheses or catheters
    • A61L17/14Post-treatment to improve physical properties
    • A61L17/145Coating
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/28Materials for coating prostheses
    • A61L27/34Macromolecular materials
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/50Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
    • A61L27/58Materials at least partially resorbable by the body
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L31/00Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
    • A61L31/08Materials for coatings
    • A61L31/10Macromolecular materials
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L31/00Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
    • A61L31/14Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
    • A61L31/148Materials at least partially resorbable by the body
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L31/00Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
    • A61L31/14Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
    • A61L31/18Materials at least partially X-ray or laser opaque
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07HSUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
    • C07H13/00Compounds containing saccharide radicals esterified by carbonic acid or derivatives thereof, or by organic acids, e.g. phosphonic acids
    • C07H13/02Compounds containing saccharide radicals esterified by carbonic acid or derivatives thereof, or by organic acids, e.g. phosphonic acids by carboxylic acids
    • C07H13/08Compounds containing saccharide radicals esterified by carbonic acid or derivatives thereof, or by organic acids, e.g. phosphonic acids by carboxylic acids having the esterifying carboxyl radicals directly attached to carbocyclic rings
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07HSUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
    • C07H17/00Compounds containing heterocyclic radicals directly attached to hetero atoms of saccharide radicals
    • C07H17/02Heterocyclic radicals containing only nitrogen as ring hetero atoms

Abstract

The present invention discloses a radiographic contrasting agent containing multiple aromatic groups, each of which is substituted with at least three halogen atoms. The radiographic contrasting agent can initiate a polymerization process. The present invention also discloses a radio-opaque polymeric material that comprises a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto.
The radio-opaque polymeric material provides enhanced contrasting intensity in radiographic imaging. The radio-opaque polymeric material can be applied on at least a portion of one surface of a medical device. The radio-opaque polymeric material can also be used to construct a medical device, a component thereof, or a portion of a component thereof.

Description

TITLE
RADIOGRAPHIC CONTRASTING AGENTS AND RADIO-OPAQUE
POLYMERIC MATERIALS FOR MEDICAL DEVICES
Reference to Related Applications This application is a division of co-pending Canadian Patent Application Serial Number 2,570,410 filed December 6, 2006.
Field of Invention The present invention relates to a radiographic contrasting agent that can initiate a polymerization process and a radio-opaque io polymeric material comprising a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto.
Background of Invention Biodegradable polymers have been widely used to construct medical devices, particularly implantable medical devices. Compared to the conventional metallic material, biodegradable polymers offer many advantages. First, biodegradable polymers are conformable and flexible, thereby causing less stress to the biological tissues. Second, medical implants made from biodegradable polymers do not require a second surgical intervention for removal. Third, the biodegradable polymers may be used to enhance the therapeutic effect of a medical implant. For example, a fractured bone that has been fixated with a rigid metal implant has a tendency for refracture upon removal of the metal implant because the stress is borne by the rigid metal, so the bone has not been able to carry sufficient load during the healing process. In contrast, a biodegradable polymer can be tuned to degrade at a certain rate so that an implant prepared therefrom will slowly transfer load to the healing bone. In addition, biodegradable polymers are useful in drug delivery systems. For example, a therapeutic agent can be admixed with a biodegradable polymer to form a polymer matrix. The release rate of the therapeutic agent in such a polymer matrix can be controlled by adjusting the degradation rate of the biodegradable polymer.
Biodegradable polymers can be either natural or synthetic. In general, synthetic polymers offer greater advantages than natural materials since the synthetic polymers can be tailored to give the desirable properties according to their intended use. Synthetic polymers also offer better consistency and uniformity than natural polymers do. Furthermore, unlike io natural materials, synthetic polymers cause little immunogenic responses after implantation. Common synthetic biodegradable polymers include polyglycolide, polylactide, poly(lactide-co-glycolide), polydioxanone, polycaprolactone, poly(hydroxyl butyrate), poly(trimethylene carbonate), polyphosphoester, polyphosphazene, and other poly(esteramide).
However, most biodegradable polymers are not radio-opaque.
Consequently, medical devices made from those biodegradable polymers cannot be visualized by means of radiographic imaging. The ability to see the radiographic image of a medical device being used in, or implanted within, the body is very important since radiographic imaging provides a physician the ability to monitor and adjust the medical device during operation. For some medical implant applications, X-ray visibility is mandatory.
To achieve desirable radio-opacity in polymeric materials, one conventional method utilizes inorganic radiographic contrasting agents, such as barium sulfate, zirconium dioxide, or bismuth halides as additives or fillers in the polymeric material to form a radio-opaque polymeric matrix. However, these inorganic agents do not mix well with polymeric materials and may cause phase separation in the radio-opaque polymeric matrix. The phase separation problem is further aggravated since high concentrations (around 10%, and often times 20-30% by weight) of these inorganic radiographic contrasting agents are routinely used to obtain the required radio-opacity.
The incompatibility between the polymeric and inorganic phases compromises the physicomechanical properties of the polymer matrix.
Another disadvantage of using inorganic radiographic contrasting agents is the toxicity to tissues caused by the leach-out of these inorganic agents.
An alternative approach to introduce radio-opacity into polymeric materials is to synthesize polymers having covalently bound lo bromine or iodine atoms that may produce a radiographic contrasting effect (See U.S. Patent No. 6,426,145). One radio-opaque composition of the prior art comprises a polymer having a non-leachable radio-opaque moiety covalently attached to the polymer (See U.S. Patent No. 6,599,448), wherein the non-leachable radio-opaque moiety includes halogen substituted aromatic groups. The prior art has also disclosed a radio-opaque polymeric material comprising a diphenol-based monomer unit substituted with at least one bromine or iodine atom (See U.S. Patent No. 6,852,308). However, preparations of these prior art radio-opaque polymers require synthesis of radiographic contrasting monomer units, which may increase the technical complexity and production cost.
Thus, there remains a need for a non-leachable radiographic contrasting agent that can provide enhanced contrasting intensity and a radio-opaque polymeric material that can be readily prepared from such a non-leachable radiographic contrasting agent and common biodegradable monomers.
Summary of the Invention Accordingly, the present invention provides a radiographic contrasting agent comprising a monosaccharide backbone or an aliphatic or alicyclic backbone of 2 to 12 carbon atoms, a reactive nucleophilic group, and at least two halogen-substituted aromatic groups, wherein each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone or the aliphatic or alicyclic backbone through a linkage group, wherein the linkage group is oxygen, sulfur, -NH-, -0(C0)-, -(C0)0-, -NH(C0)-, -(CO)NH-, -0(S02)-, -(S02)0-, -0(S0)-, -(S0)0-, -NH(S02)-, -(S02)NH-, -NH(S0)-, -(SO)NH-, or triazole.
Preferably, the radiographic contrasting agent has the following structure:
Y
R-N-CH2 _________________________________________________ Y
xY
,rn (I) wherein R is a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms;
X is oxygen, sulfur, -NH, -0(C0)-, -(C0)0-, -NH(C0)-, -(CO)NH-, -0(S02)-, -(S02)0-, -0(S0)-, -(S0)0-, -NH(S02)-, -(S02)NH-, -NH(S0)-, -(SO)NH-, or triazole; Y is an aromatic group substituted with at least three halogen atoms; n and m are the same or different, and are independently zero or an integer of 1 to 4. Preferably, R is hydrogen; X is ¨0(C0)¨, ¨
NH(C0)¨, or triazole; and n and m are both zero.
The present invention also provides a radio-opaque polymeric material, comprising a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto, wherein the at least one radiographic contrasting moiety is covalently attached to the biodegradable polymer through a functional group derived from a nucleophilic reaction, and the at least one radiographic contrasting moiety comprises a monosaccharide backbone or an aliphatic or alicyclic backbone of 2 to 12 carbon atoms, and at least two halogen-substituted aromatic groups, wherein each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone or the aliphatic or alicyclic backbone through a linkage group, wherein the linkage group is oxygen, sulfur, ¨NH¨, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨0(S02)¨, ¨
(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨NH(S02)¨, ¨(S02)NH¨, ¨NH(S0)¨, ¨(SO)NH¨, or triazole.
Preferably, R is hydrogen; X is ¨0(C0)¨, ¨NH(C0)¨, or triazde; and n and m are both zero.
Preferably, the radiographic contrasting moiety covalently attached to the biodegradable polymer has the following structure:
Y
¨N¨ CH2 ________________________________________________ Y
n m (II) wherein R is a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms;
X is oxygen, sulfur, ¨NH, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨
0(S02)¨, ¨(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨NH(S02)¨, ¨(S02)NH¨, ¨NH(S0)¨, -(SO)NH¨, or triazole; Y is an aromatic group substituted with at least three halogen atoms; n and m are the same or different, and are independently zero or an integer of 1 to 4.
In another aspect, the present invention provides a medical device, wherein at least one portion of the medical device is radio-opaque, io the at least one radio-opaque portion of the medical device comprising a radio-opaque polymeric material, which comprises a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto, wherein the at least one radiographic contrasting moiety is covalently attached to the biodegradable polymer through a functional group derived from a nucleophilic reaction, and the at least one radiographic contrasting moiety comprises a monosaccharide backbone or an aliphatic or alicyclic backbone of 2 to 12 carbon atoms, a reactive nucleophilic group, and at least two halogen-substituted aromatic groups, wherein each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone or the aliphatic or alicyclic backbone through a linkage group, wherein the linkage group is oxygen, sulfur, ¨NH¨, ¨0(C0)¨, ¨(C0)0¨, ¨
NH(C0)¨, ¨(CO)NH¨, ¨0(S02)¨, ¨(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨NH(S02)¨, ¨(S02)NH¨, ¨NH(S0)¨, ¨(SO)NH¨, or triazole.
Detailed Description of the Invention The present invention provides a radiographic contrasting agent comprising a monosaccharide backbone or an aliphatic or alicyclic backbone of 2 to 12 carbon atoms, a reactive nucleophilic group, and at least two halogen-substituted aromatic groups. By "monosaccharide", it is meant a simple sugar that cannot be hydrolyzed to smaller units. Empirical formula for monosaccharide is (CH20)n, wherein n is an integer of 1 to 9. As used herein, "an aliphatic backbone" denotes an organic moiety consisting of carbon atoms linked in open chains, and "an alicyclic backbone" denotes an organic moiety consisting of carbon atoms forming one or more rings that lo are not aromatic. The aliphatic or alicyclic backbone of the present invention contains 2 to 12 carbon atoms. By "a reactive nucleophilic group", it is meant a reactive chemical moiety having an affinity to atomic nuclei.
Reactive nucleophilic groups suitable for the present invention include, but are not limited to: NRH, OH, and SH; wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Each of the at least two halogen-substituted aromatic groups in the inventive radiographic contrasting agent is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone or the aliphatic or alicyclic backbone through a linkage group. The linkage group is selected from oxygen, sulfur, ¨NH¨, -0(C0)-, -(C0)0-, ¨NH(C0)¨, ¨(CO)NH--, ¨0(S02)¨, ¨(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨
NH(S02)¨, ¨(302)NH¨, ¨NH(S0)¨, ¨(SO)NH¨, and triazole. As used herein, "(CO)"
denotes a carbonyl moiety; "(SO)" denotes a sulfinyl moiety; and "(SO2)"
denotes a sulfonyl moiety. The linkage group links the monosaccharide backbone or aliphatic or alicyclic backbone and the at least two halogen-substituted aromatic groups through covalent bonds.
The linkage group expressed as "¨linkage¨" denotes a linkage in the manner as follows: (the monosaccharide backbone or the aliphatic or alicyclic backbone)¨linkage¨(one of the at least two halogen-substituted aromatic groups). For example, "¨(C0)0¨" denotes a linkage as follows:
(the monosaccharide backbone or the aliphatic or alicyclic backbone)¨
(C0)0¨(one of the at least two halogen-substituted aromatic groups).
Preferably, the linkage group of the present invention is ¨NH(C0)¨, ¨0(C0)¨, or triazole. The term "triazole" as used herein includes both 1,2,3-triazole and 1,2,4-triazole. When the linkage group is triazole, the io monosaccharide backbone or the aliphatic or alicyclic backbone and the at least two halogen-substituted aromatic group are linked through one of the two carbon atoms, and the nitrogen atom at the 4 position in the case of 1,2,4-triazole or the nitrogen atom at the 3 position in the case of 1,2,3-triazole.
The monosaccharide backbones suitable for the present invention include, but are not limited to: monose, diose, triose, tetrose, pentose, hexose, heptose, octose, and nonose. Preferably, the monosaccharide backbone of the present invention contains 3 to 7 carbon atoms. The aliphatic backbones suitable for the present invention include, but are not limited to: ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and analogs or isomers thereof. The alicyclic backbones suitable for the present invention include, but are not limited to:
cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooxtanene, and analogs or isomers thereof. Preferably, the aliphatic or alicyclic backbone is an aliphatic or alicyclic moiety having 4 to 8 carbon atoms.
It is preferable that the radiographic contrasting agent of the present invention contains at least three halogen-substituted aromatic groups. By "a halogen-substituted aromatic group", it is meant an aromatic group having at least one halogen substituent. By "an aromatic group", it is meant a cyclic organic compound containing multiple conjugated double bonds. The halogen-substituted aromatic group of the present invention may be halogen-substituted carbocyclic, heterocyclic, or polycyclic compounds. Halogen-substituted aromatic groups suitable for the present invention include, but are not limited to: halogen-substituted benzene, toluene, xylenes, styrenes, pyridine, furan, naphthalene, anthracene, phenanthrene, indole, quinoline, and isoquinoline. Preferably, the halogen-io substituted aromatic group of the present invention is halogen-substituted benzene. Each of the halogen-substituted aromatic groups of the present invention is substituted with at least three halogen atoms. Preferably, the at least three halogen atoms are bromine, iodine, or combinations thereof.
More preferably, the halogen-substituted aromatic group of the present invention is substituted with at least three iodine atoms. In one preferred embodiment of the present invention, the halogen-substituted aromatic group is 2,3,5-triiodobenzene.
Preferably, the radiographic contrasting agent of the present invention has the following structure:
, m Y

n X
(I) wherein R is a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms;
X is oxygen, sulfur, ¨NH, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨
0(S02)¨, -(S02)0-, -0(S0)-, -(S0)0-, -NH(S02)-, -(S02)NH-, -NH(S0)-,-(SO)NH-, or triazole; Y is an aromatic group substituted with at least three halogen atoms; n and m are the same or different, and are independently zero or an integer of 1 to 4. The alkyl groups suitable for the present invention include, but are not limited to: methyl, ethyl, n-propyl and n-butyl.
Preferably, R is a hydrogen atom. More preferably, R is a hydrogen atom and X is -0(C0)-, -NH(C0)-, or triazole. Most preferably, R is a hydrogen atom; X is -0(C0)-, -NH(C0)-, or triazole; and m and n are both zero. It is preferable that the aromatic group substituted with at least three halogen io atoms is a benzene group substituted with at least three halogen atoms. It is also preferable that the at least three halogen atoms are bromine, iodine, or combinations thereof. It is more preferable that the aromatic group substituted with at least three halogen atoms is an aromatic group substituted with at least three iodine atoms. In one preferred embodiment of the present invention, the aromatic group aromatic group substituted with at least two halogen atoms is 2,3,5-triiodobenzene.
In one embodiment of the present invention, the radiographic contrasting agent of formula (I) has the following structure:
H2N -cH2 =

(III).
In another embodiment of the present invention, the inventive radiographic contrasting agent has one of the following structures:
R2 ,OH R2 õ0, 0 -Ri R (IV) , R
R1 (V) wherein õN.õ.
R1 = ; R2 = R3.
R3 = NHR, OH, or SH;
R = hydrogen or C1-C4 alkyl; and q = an integer of 1-4.
The radiographic contrasting agent of the present invention can be prepared through reactions between an organic compound containing polyhydric alcohol or polyamine and an aromatic compound substituted with multiple halogen atoms.
In one embodiment of the present invention, the radiographic contrasting agent of the present invention is first synthesized in its protected form through an esterification of a polyhydric alcohol and 2,3,5-triiodobenzoic acid chloride, as shown in Scheme 1. The protection group 15 may be any protection groups that are suitable for protecting amines and compatible with the esterification process. Preferably, the protection group is a base-liable protection group, such as N-9-fluorenylmethyloxycarbonyl (Fmoc). The term "DMAP" as used herein denotes 4-(dimethylamino) pyridine or a hydrochloride salt thereof.
I Si I
Scheme 1:

HN -__/(:)Fl + 3 Ci i I
DMAP
, HN-..._C) I
II
Base le I

PG = protection group I
i Then the protection group is removed by a deprotection process providing the inventive radiographic contrasting agent, as shown in Scheme 2. The reaction condition of the deprotection process is determined by the nature of the protection group. For a base-liable protection group, the deprotection is typically conducted in the presence of a strong base.
Scheme 2:
I el I I 401 I
I I I I

HNIC) I H2N-70 1410 I
I
PG ----0 0 I deprotection ________________________________________________ ..
40 I op I

I I
I PG = protection group I
(III) In another embodiment of the present invention, the inventive lo radiographic contrasting agent is prepared from a monosaccharide through a Huisgen [3+2] cycloaddition under mild conditions, as illustrated in Scheme 3. Since the monosaccharide is non-synthetic, natural molecule containing polyhydric alcohol, the inventive radiographic contrasting agent derived therefrom has enhanced biocompatibility. As used herein, the term "TEA"
denotes triethylamine.
Scheme 3:
OH i CI TEA /
DMAP
HO-y."OH
OH .
.õ OH
OY
I 0 I 0 CuSO4, R1 R1 sodium ascorbate Ri o R1 (IV) R1 N N R --^---. 3 R3 = NHR, OH, or SH;
' -- ; R2 = _ q . R = hydrogen or C1-C4 alkyl; and q = an integer of 1-4.
The reactive nucleophilic group in the inventive radiographic contrasting agent may react with an electrophilic group (e.g., a carbonyl group) in a biodegradable monomer initiating a polymerization process.
Thus, the inventive radiographic contrasting agent may be an initiator for the polymerization of a biodegradable monomer producing a biodegradable polymer having the initiator, i.e., the inventive radiographic contrasting agent, covalently attached thereto. By "biodegradable polymer", it is meant a polymer that can be degraded or decomposed by natural biological processes, as by the action of bacteria, plants, or animals. Biodegradable polymers are also known as bioabsorbable polymers or biodissolvable polymers. Biodegradable polymers suitable for the present invention include, but are not limited to: polyglycolide, polylactide, polydioxane, polycaprolactone, poly(lactide-co-glycolide), polyhydroxybutyrate, poly(trimethylene carbonate), other poly esters, and a mixture thereof.
In one embodiment of the present invention, the inventive radiographic contrasting agent of formula (I) initiates the ring-opening polymerization of lactide producing a polylactide having the radiographic contrasting agent attached thereto, as shown in Scheme 4. The term "Sn(0c)2" as used herein denotes stannous octoate. X, Y, n and m are the same as defined hereinbefore.
Scheme 4:

Sn(002 Ra R4-NH2 + p/2 0 p OH
o (VI) Y
R4= ¨ CH2Y = P = an integer of 2 to 5000 )(õ
XY
m The present invention also provides a radio-opaque polymeric material comprising a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto. The at least one radiographic contrasting moiety is covalently attached to the biodegradable polymer through a functional group derived from a nucleophilic reaction. The at least one radiographic contrasting moiety comprises a monosaccharide backbone or an aliphatic or alicyclic backbone of 2 to 12 carbon atoms and at least two halogen-substituted aromatic groups. Each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone or the aliphatic or alicyclic backbone through a linkage group, wherein the linkage group is selected from oxygen, sulfur, ¨
NH¨, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨0(S02)¨, ¨(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨NH(S02)¨, ¨(S02)NH¨, ¨NH(S0)¨, ¨(SO)NH¨, and triazole. The term "a nucleophilic reaction" as used herein denotes a chemical reaction between a reactive nucleophilic group and a carbonyl group. The term "a functional group derived from a nucleophilic reaction" as used herein denotes a functional group formed through a nucleophilic reaction between a reactive nucleophilic group and a carbonyl group. By "a reactive nucleophilic group", it is meant a reactive chemical moiety having an affinity to atomic nuclei. Reactive nucleophilic groups suitable for the present invention include, but are not limited to: NRH, OH, and SH; wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
Preferably, the radiographic contrasting moiety in the inventive radio-opaque polymeric material has the following structure:
ThX<iY
¨N ¨ CH2 Y
n m (II) wherein R is a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms;
X is oxygen, sulfur, ¨NH, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨
0(S02)¨, ¨(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨NH(S02)¨, ¨(S02)NH¨, ¨NH(S0)¨, ¨
(SO)NH¨, or triazole; Y is an aromatic group substituted with at least three halogen atoms; n and m are the same or different, and are independently zero or an integer of 1 to 4. Preferably, R is a hydrogen atom; and X is ¨
0(C0)¨, ¨NH(C0)¨, or triazole. More preferably, R is a hydrogen atom; X is ¨0(C0)¨, ¨NH(C0)¨, or triazole; and n and m are both zero. It is preferable that the aromatic group substituted with at least three halogen atoms is a benzene group substituted with at least three halogen atoms. It is also preferable that the at least three halogen atoms are bromine, iodine, or combinations thereof. It is more preferable that the aromatic group substituted with at least three halogen atoms is an aromatic group substituted with at least three iodine atoms. In one preferred embodiment of the present invention, the aromatic group aromatic group substituted with at least two halogen atoms is 2,3,5-triiodobenzene.
In the present invention, the biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto may be synthesized by initiating the polymerization of a biodegradable monomer with the inventive radiographic contrasting agent. The reactive nucleophilic group in the inventive radiographic contrasting agent can react with a carbonyl group in the biodegradable monomer forming a functional group and further initiating a polymerization process. The biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto comprises monomer units that include, but are not limited to:
glycolide, lactide, dioxane, caprolactone, trimethylene carbonate, hydroxybutyrate, and combinations thereof. Therefore, the inventive biodegradable polymer can be readily prepared from common biodegradable monomers, such as lactide, glycolide, caprolactone, dioxane, trimethylene carbonate, hydroxybutyrate, or combinations thereof. In one embodiment of the present invention, the biodegradable polymer having at least one io radiographic contrasting moiety is prepared through the synthetic route shown in Scheme 4. Preferably, the inventive biodegradable polymer having at least one radiographic contrasting moiety contains at least two radiographic contrasting moieties, thereby having enhanced radiographic contrasting effect. The inventive biodegradable polymer having at least two radiographic contrasting moieties can be synthesized by end-capping an inventive biodegradable polymer having one radiographic contrasting moiety with a derivative of the radiographic contrasting agent of formula (I), (IV), or (V).
In one embodiment of the present invention, the inventive radiographic contrasting agent is transformed to an acid derivative thereof, as shown in Scheme 5. X, Y, n, and m are the same as defined hereinbefore.
Scheme 5:
R4-NH2 + CICH2COOH ---,- R4NHCH2COOH
R4 = ¨ CH2 .--------2t-n---X-4--------+;-"--n Y
----7F-I x---:
' -..,_2.¨y , m Next, the inventive biodegradable polymer of formula (VI) is end-capped with the acid derivative of the inventive radiographic contrasting agent providing an inventive biodegradable polymer having at least two radiographic contrasting moieties, as shown in Scheme 6. The term "DMAP"
as used herein denotes 4-(dimethylamino) pyridine or a hydrochloride salt thereof. X, Y, n, and m are the same as defined hereinbefore.
Scheme 6:

N 0 p OH DMAP
H H
x";----t'n Y
R4= ¨ CH2.--, X-,:j_r_.--T,Y ; p = an integer of 2 to 5000.
X
r n -----,..4¨y m The inventive biodegradable polymer not only possesses the desirable biocompatibility and physicomechanical properties (e.g., strength, fatigue, and smoothness), but also has radio-opacity for visualization in radiographic imaging. The mechanical strength and the degradation time of the inventive biodegradable polymer can be tuned by adjusting the molecular weight or composition thereof. The radiographic contrast intensity of the inventive biodegradable polymer can be adjusted by varying the ratio of the at least one radiographic contrasting moiety in the inventive biodegradable polymer or modifying the structure of the at least one radiographic contrasting moiety. The inventive biodegradable polymer is soluble in organic solvents and miscible with the bulk polymeric materials used to construct a medical device. The inventive biodegradable polymer is not soluble in water and do not leach out during the manufacture process or initial implantation period. Therefore, the inventive radio-opaque biodegradable polymer is suitable for the fabrication and use of medical devices interfacing with biological tissues, particularly implantable medical devices. Using similar reaction schemes as shown in Schemes 4 to 6, monosaccharide-based radiographic contrasting agents can be employed as polymerization initiators to prepare the inventive biodegradable polymers.
In another aspect, the present invention provides a medical device, wherein at least one portion of the medical device is radio-opaque.
The at least one radio-opaque portion of the medical device comprises a radio-opaque polymeric material, which comprises a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto. The at least one radiographic contrasting moiety is covalently attached to the biodegradable polymer through a functional group derived from a nucleophilic reaction. The at least one radiographic contrasting moiety comprises a monosaccharide backbone or an aliphatic or alicyclic backbone of 2 to 12 carbon atoms and at least two halogen-substituted aromatic groups. Each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone or the aliphatic or alicyclic backbone through a linkage group, wherein the linkage group is selected from oxygen, sulfur, ¨NH¨, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨
0(S02)¨, ¨(S02)0¨, ¨0(S0)¨, ¨(S0)0¨, ¨NH(S02)¨, ¨(S02)NH¨, ¨NH(S0)¨, ¨(SO)NH¨, and triazole.
In one embodiment of the present invention, the at least one radiographic contrasting moiety has the following structure:
Y
N CH2¨ Y
xY
m (II) wherein R is a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms;
X is oxygen, sulfur, ¨NH, ¨0(C0)¨, ¨(C0)0¨, ¨NH(C0)¨, ¨(CO)NH¨, ¨
0(S02)-, -(S02)0-, -0(S0)-, -(S0)0-, -NH(S02)-, ¨(S02)NH¨, ¨NH(S0)¨, ¨
(SO)NH¨, or triazole; Y is an aromatic group substituted with at least three halogen atoms; n and m are the same or different, and are independently zero or an integer of 1 to 4. Preferably, R is a hydrogen atom; and X is -0(C0)¨, ¨NH(C0)¨, or triazole. More preferably, R is a hydrogen atom; X is ¨0(C0)¨, ¨NH(C0)¨, or triazole; and n and m are both zero. Preferably, the inventive biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto contains at least two radiographic contrasting moieties, thereby having enhanced radiographic contrasting effect. Biodegradable polymers suitable for the present invention comprise monomer'units that include, but are not limited to: glycolide, lactide, dioxane, caprolactone, trimethylene carbonate, hydroxybutyrate, and combinations thereof.
In the present invention, the radio-opaque portion of the medical device may be at least a portion of one surface of the medical device, a component of the medical device, or a portion of a component of the medical device. The radio-opaque portion of the medical device may be in any shape or size depending upon the intended use and the fabrication method of the medical device. When all surfaces of the medical device are covered with the inventive radio-opaque biodegradable polymeric material or the whole medical device is prepared from the inventive radio-opaque biodegradable polymeric material, the whole medical device is radio-opaque.
lo Preferably, the medical device of the present invention is implantable.
Examples of the medical devices suitable for the present invention include, but are not limited to: wound closure devices, such as, sutures, staples, and mesh; orthopedic fixation devices, such as, bone fracture fixation implants and bone augmentation implants; intestinal devices, such as, anastomosis rings and ligating clips; cardiovascular devices, such as, vascular grafts and drug elution stents; dental implants; nerve growth conduits; and other implantable medical devices. The inventive radio-opaque biodegradable polymeric material may be applied on at least a portion of one surface of a medical device using cast, spray, spin, dipping, or other methods known to one skilled in the art. The medical device or a component thereof can be constructed from the inventive radio-opaque biodegradable polymeric material using injection molding, compression molding, extrusion, or other methods know to one skilled in the art to construct polymeric medical devices.
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the scope of the invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated but fall within the scope of the appended claims.

Claims (4)

1. A radiographic contrasting agent comprising a monosaccharide backbone, a reactive nucleophilic group, and at least two halogen-substituted aromatic groups, wherein each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone through a linkage group, wherein the linkage group is oxygen, sulfur, -NH-, -O(CO)-, -(CO)O-, -NH(CO)-, -(CO)NH-, -O(SO2)-, -(SO2)O-, -O(SO)-, -(SO)O-, -NH(SO2)-, -(SO2)NH-, -NH(SO)-, -(SO)NH-, or triazole.
2. The radiographic contrasting agent of claim 1, having one of the following structures:
wherein R1 = R3 = NHR, OH, or SH;
R = hydrogen or C1-C4 alkyl; and q = an integer of 1-4.
3. A radio-opaque polymeric material comprising a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto, wherein the at least one radiographic contrasting moiety is covalently attached to the biodegradable polymer through a functional group derived from a nucleophilic reaction, and the at least one radiographic contrasting moiety comprises a monosaccharide backbone and at least two halogen-substituted aromatic groups, wherein each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone a linkage group, wherein the linkage group is oxygen, sulfur, -NH-, -O(CO)-, -(CO)O-, -NH(CO)-, -(CO)NH-, -O(SO2)-, -(SO2)O-, -O(SO)-, -(SO)O-, -NH(SO2)-, -(SO2)NH-, -NH(SO)-, -(SO)NH-, or triazole.
4. A medical device, wherein at least one portion of the medical device is radio-opaque, the at least one radio-opaque portion of the medical device comprising a radio-opaque polymeric material, which comprises a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto, wherein the at least one radiographic contrasting moiety is covalently attached to the biodegradable polymer through a functional group derived from a nucleophilic reaction, and the at least one radiographic contrasting moiety comprises a monosaccharide backbone and at least two halogen-substituted aromatic groups, wherein each of the at least two halogen-substituted aromatic groups is substituted with at least three halogen atoms and is covalently attached to the monosaccharide backbone a linkage group, wherein the linkage group is oxygen, sulfur, -NH-, -O(CO)-, -(CO)O-, -NH(CO)-, -(CO)NH-, -O(SO2)-, -(SO2)O-, -O(SO)-, -(SO)O-, -NH(SO2)-, -(SO2)NH-, -NH(SO)-, -(SO)NH-, or triazole.
CA2820238A 2005-12-13 2006-12-06 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices Expired - Fee Related CA2820238C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US11/301,874 2005-12-13
US11/301,874 US20070134163A1 (en) 2005-12-13 2005-12-13 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices
CA2570410A CA2570410C (en) 2005-12-13 2006-12-06 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
CA2570410A Division CA2570410C (en) 2005-12-13 2006-12-06 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices

Publications (2)

Publication Number Publication Date
CA2820238A1 true CA2820238A1 (en) 2007-06-13
CA2820238C CA2820238C (en) 2015-11-10

Family

ID=38139593

Family Applications (2)

Application Number Title Priority Date Filing Date
CA2570410A Expired - Fee Related CA2570410C (en) 2005-12-13 2006-12-06 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices
CA2820238A Expired - Fee Related CA2820238C (en) 2005-12-13 2006-12-06 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CA2570410A Expired - Fee Related CA2570410C (en) 2005-12-13 2006-12-06 Radiographic contrasting agents and radio-opaque polymeric materials for medical devices

Country Status (5)

Country Link
US (2) US20070134163A1 (en)
EP (1) EP1815871B1 (en)
JP (1) JP5068524B2 (en)
AT (1) ATE551074T1 (en)
CA (2) CA2570410C (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7410606B2 (en) 2001-06-05 2008-08-12 Appleby Michael P Methods for manufacturing three-dimensional devices and devices created thereby
US7790141B2 (en) * 2003-08-11 2010-09-07 Pathak Holdings, Llc Radio-opaque compounds, compositions containing same and methods of their synthesis and use
EP2559533B1 (en) 2008-09-26 2020-04-15 United Technologies Corporation Casting
DE102009036817A1 (en) * 2009-08-10 2011-02-17 Acoredis Gmbh Occlusion device, useful e.g. for closing the heart defects in a patient and other abnormal body openings, comprises mesh of fibers or film body of highly flexible, elastic materials, where the device is introduced through e.g. catheter
US9180137B2 (en) 2010-02-09 2015-11-10 Bone Support Ab Preparation of bone cement compositions
US8882730B2 (en) 2010-03-12 2014-11-11 Kci Licensing, Inc. Radio opaque, reduced-pressure manifolds, systems, and methods
US8813824B2 (en) 2011-12-06 2014-08-26 Mikro Systems, Inc. Systems, devices, and/or methods for producing holes
ES2671122T3 (en) 2013-02-20 2018-06-05 Bone Support Ab Enhanced hardening of hardenable bone substitute
US11213596B2 (en) 2018-03-12 2022-01-04 Boston Scientific Scimed, Inc. Radiocontrast agents, scavenging methods, and scavenging system
EP4069316A1 (en) * 2019-12-04 2022-10-12 Universität Zürich Contrast agent for 3d ex vivo imaging of vascular and tubular structures in the kidney

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1245853B (en) * 1990-11-16 1994-10-25 Bracco Spa 1,3-BIS (3- (MONO OR POLYHYDROXY) ACYLAMINE-5- (MONO OR POLYHYDROXY-ALCHYL) AMINOCARBONYL-2,4,6-TRIIODE-BENZOYL-AMINO) -HYDROXY- OR HYDROXY-ALCHYL-PROPANE, THEIR METHOD OF PREPARATION AND ROENTGENOGRAPHIC CONTRAST MEANS THAT CONTAIN THEM
AU642066B2 (en) * 1991-01-25 1993-10-07 Nanosystems L.L.C. X-ray contrast compositions useful in medical imaging
AU737151B2 (en) 1997-11-07 2001-08-09 Rutgers, The State University Radio-opaque polymeric biomaterials government license rights
US8029561B1 (en) 2000-05-12 2011-10-04 Cordis Corporation Drug combination useful for prevention of restenosis
US6723746B2 (en) 1998-09-08 2004-04-20 Veritas Pharmaceuticals, Inc. Functional radiographic imaging methods and agents
US6426145B1 (en) * 1999-05-20 2002-07-30 Scimed Life Systems, Inc. Radiopaque compositions for visualization of medical devices
US6599448B1 (en) * 2000-05-10 2003-07-29 Hydromer, Inc. Radio-opaque polymeric compositions
JP2004231622A (en) * 2003-02-03 2004-08-19 Fuji Photo Film Co Ltd Pentose derivative having iodoaryl group
ES2452731T3 (en) 2003-06-19 2014-04-02 Vascular Therapies, Llc Vascular closure device
US7875282B2 (en) 2004-03-22 2011-01-25 Cordis Corporation Coated medical device for local vascular delivery of Panzem® in combination with rapamycin to prevent restenosis following vascular injury
US20050232965A1 (en) 2004-04-15 2005-10-20 Robert Falotico Local administration of a combination of rapamycin and 17 beta-estradiol for the treatment of vulnerable plaque
US20060292077A1 (en) * 2005-03-18 2006-12-28 Zhao Jonathon Z Dendritic and star-shaped contrast agents for medical devices and bioabsorbable radiopaque bulk material and method for producing same

Also Published As

Publication number Publication date
JP5068524B2 (en) 2012-11-07
CA2570410A1 (en) 2007-06-13
EP1815871B1 (en) 2012-03-28
US7771705B2 (en) 2010-08-10
US20090209745A1 (en) 2009-08-20
CA2820238C (en) 2015-11-10
EP1815871A3 (en) 2007-12-26
ATE551074T1 (en) 2012-04-15
US20070134163A1 (en) 2007-06-14
JP2007161713A (en) 2007-06-28
EP1815871A2 (en) 2007-08-08
CA2570410C (en) 2015-03-24

Similar Documents

Publication Publication Date Title
CA2820238C (en) Radiographic contrasting agents and radio-opaque polymeric materials for medical devices
US9212259B2 (en) Nitric oxide delivery system using thermosensitive synthetic polymers
JP5581202B2 (en) Dihydroxybenzoate polymer and use thereof
JP6046331B2 (en) Phenyl ester side chain to increase polymer absorbency
JP5746629B2 (en) Biodegradable polymer-bioactive moiety complex
ES2718681T3 (en) Resorbable Phenolic Polymers
ES2628931T3 (en) Multi-block segmented copolymers of biodegradable separate phases and release of biologically active polypeptides
CA1340354C (en) Periodontium-regenerative materials
JP5671463B2 (en) Linear polyester amides from aminophenol esters
JP6592437B2 (en) Polymeric biomaterials derived from monomers containing hydroxy acids and phenolic compounds and their medical use
US20070117959A1 (en) Novel polyesters
US10105467B2 (en) Biocompatible polymer compositions for tissue void filling
CA2568827C (en) Organic radiographic contrasting agents for medical devices
Wischke et al. AB‐polymer Networks with Cooligoester and Poly (n‐butyl acrylate) Segments as a Multifunctional Matrix for Controlled Drug Release
ES2773179T3 (en) Coated medical article for drug release
CN107207696A (en) Biodegradable polymer
US8173765B2 (en) Polymers, uses and methods of manufacture thereof

Legal Events

Date Code Title Description
EEER Examination request

Effective date: 20130625

MKLA Lapsed

Effective date: 20191206