Degradation of and l-glutamic acid homopolymers and copolymers by papain

Pytela, Jindšrich; Kotva, R.; Metalová, M.; Rypášcek, Františsek

doi:10.1016/0141-8130(90)90003-s

Cited by 21 publications

(4 citation statements)

References 15 publications

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“…Poly(hydroxyethyl l -glutamine) (PHEG) was selected as a starting polymer, as PHEG is known to be water-soluble, biocompatible, and degradable by isolated enzymes (e.g. papain, chymotrypsin, and Pronase) as well as cocktails of lysozomal extracts and kidney homogenates ( − ). Subsequently, structure−activity relationships were established by replacing the hydroxyethyl side group with other hydroxyalkyl groups and selecting l -asparagine as backbone monomer instead of glutamine.…”

Section: Introductionmentioning

confidence: 99%

A Novel Family ofl-Amino Acid-Based Biodegradable Polymer−Lipid Conjugates for the Development of Long-Circulating Liposomes with Effective Drug-Targeting Capacity

et al. 2003

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The objective of this study was to develop biodegradable polypeptide-lipid conjugates for the design of polymer-coated long-circulating liposomes (LCL). Lipid conjugates of poly(hydroxyalkyl L-asparagine/L-glutamine) were synthesized and incorporated into 0.15 microm dipalmitoyl phosphatidylcholine (DPPC)-cholesterol liposomes. Circulation times and biodistribution were assessed in rats using a radioactive lipid marker. Evaluation of the therapeutic activity of prednisolone phosphate loaded in 0.1 microm PHEA-DPPC-cholesterol liposomes in a rat experimental arthritis model was performed to demonstrate the drug-targeting potential of the polymer-coated liposomes. Coating of liposomes with poly(hydroxyethyl L-asparagine) (PHEA) and poly(hydroxyethyl L-glutamine) (PHEG) extended the circulation half-life to a similar extent as poly(ethylene glycol) (PEG), which is normally used for the preparation of LCL. Glutamine polymers with a hydroxypropyl or a hydroxybutyl group instead of hydroxyethyl group also yield prolonged circulation, however, not to the same extent as PHEA/G. The pharmacokinetic properties of PHEA-liposomes were independent of the lipid dose even at very low lipid doses of around 50 nmol per rat. PLP was successfully entrapped in PHEA-liposomes. These liposomes were shown to be stable in the circulation and equally effective in rat experimental arthritis as PLP encapsulated in PEG-liposomes. PHEA and PHEG are attractive alternative polymers for the design of LCL: their performance is similar to that of PEG-liposomes but they have the advantage of being biodegradable.

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Section: Introductionmentioning

confidence: 99%

A Novel Family ofl-Amino Acid-Based Biodegradable Polymer−Lipid Conjugates for the Development of Long-Circulating Liposomes with Effective Drug-Targeting Capacity

et al. 2003

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“…With the increasing pH (pH > 5), the increasing charge density will decrease its degradation rate. 18 During the degradation of AZ31, an alkaline environment would be formed and a decreased degradation rate of PGA could be achieved. Moreover, glutamic acid, one of the degradation products of PGA, may neutralize the alkaline environment caused by the corrosion of AZ31.…”

Section: Discussionmentioning

confidence: 99%

Sirolimus-eluting dextran and polyglutamic acid hybrid coatings on AZ31 for stent applications

Zhao

Zhu

2015

J Biomater Appl

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Magnesium (Mg)-based cardiovascular stents are promising candidate as the next generation of novel stents. Clinical studies have revealed encouraging outcomes, but late restenosis and thrombogenesis still largely exist. Blood and vascular biocompatible coatings with drug-eluting features could be the solution to such problems. Objective This study was to investigate the feasibility of a three-layer hybrid coating on Mg alloy AZ31 with sirolimus-eluting feature for cardiovascular stent application. Materials and methods The first and third layers were low molecular weight dextran loaded with sirolimus, and the second layer was polyglutamic acid (PGA) to control sirolimus release. The hybrid coating was verified by scanning electron microscope (SEM). DC polarization and immersion tests were used to evaluate corrosion rate of the materials. Indirect cell viability and cell proliferation tests were performed by culturing cells with extract solutions of AZ31 samples. Blood compatibility was assessed using hemolysis assay. Results Coated samples had an enhanced corrosion resistance than that of uncoated controls, more PGA slower corrosion. Sirolimus had a burst release for the initial ~3 days and then a slower release until reached a plateau. The PGA thickness was able to control the sirolimus release, the thicker of PGA the slower release. The overall cell viability was extract concentration-dependent, and improved by the hybrid coatings. Cell proliferation was correlated to coating thickness and was inhibited by sirolimus. In addition, all coated AZ31 samples were non-hemolytic. Conclusion Results demonstrated that such a three-layer hybrid coating may be useful to improve the vascular biocompatibility of Mg stent materials.

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“…This linear hydrophilic polymer was proposed as a plasma expander by Neri [21][22]. Its biodegradability has been demonstrated by several research groups [23][24][25][26][27]. The hydroxyl functions can be used for attaching drugs and/or targeting moieties [28].…”

Section: Introductionmentioning

confidence: 99%

Dendritic Poly-[N-(2-Hydroxyethyl)-L-Glutamine] as Potential Drug Carrier

Winne¹,

Vanderkerken²,

Hoste³

et al. 2004

Journal of Bioactive and Compatible Polymers

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Dendritic poly-[N-(2-hydroxyethyl)-L-glutamine] (PHEG) with different molecular weights were synthesized by aminolysis of dendritic poly-(γ-benzyl-L-glutamate) (PBG), which was obtained by polymerization of the corresponding N-carboxyanhydride (NCA) with poly(amido amine) (PAMAM, starburst ® ) of the fourth generation as initiator. Dynamic light scattering (DLS) was used to determine the size of the polymeric carriers and to compare the dendritic polymer to the linear analogue. The body distribution and blood clearance of 125 I-radiolabelled linear and dendritic PHEG with similar molecular weight were investigated in female BALB/c mice.

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Degradation of and l-glutamic acid homopolymers and copolymers by papain

Cited by 21 publications

References 15 publications

A Novel Family ofl-Amino Acid-Based Biodegradable Polymer−Lipid Conjugates for the Development of Long-Circulating Liposomes with Effective Drug-Targeting Capacity

A Novel Family ofl-Amino Acid-Based Biodegradable Polymer−Lipid Conjugates for the Development of Long-Circulating Liposomes with Effective Drug-Targeting Capacity

Sirolimus-eluting dextran and polyglutamic acid hybrid coatings on AZ31 for stent applications

Dendritic Poly-[N-(2-Hydroxyethyl)-L-Glutamine] as Potential Drug Carrier

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