Physically crosslinked dextran hydrogels by stereocomplex formation of lactic acid oligomers: degradation and protein release behavior

Ideally, rationally designed tissue engineering scaffolds promote natural wound healing and regeneration. Therefore, we sought to synthesize a biomimetic hydrogel specifically designed to promote tissue repair and chose hyaluronic acid (HA; also called hyaluronan) as our initial material. Hyaluronic acid is a naturally occurring polymer associated with various cellular processes involved in wound healing, such as angiogenesis. Hyaluronic acid also presents unique advantages: it is easy to produce and modify, hydrophilic and nonadhesive, and naturally biodegradable. We prepared a range of glycidyl methacrylate-HA (GMHA) conjugates, which were subsequently photopolymerized to form crosslinked GMHA hydrogels. A range of hydrogel degradation rates was achieved as well as a corresponding, modest range of material properties (e.g., swelling, mesh size). Increased amounts of conjugated methacrylate groups corresponded with increased crosslink densities and decreased degradation rates and yet had an insignificant effect on human aortic endothelial cell cytocompatibility and proliferation. Rat subcutaneous implants of the GMHA hydrogels showed good biocompatibility, little inflammatory response, and similar levels of vascularization at the implant edge compared with those of fibrin positive controls. Therefore, these novel GMHA hydrogels are suitable for modification with adhesive peptide sequences (e.g., RGD) and use in a variety of woundhealing applications.

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“…The swollen hydrogel mesh size, , was determined with the following equation (de Jong et al, 2001;Lowman and Peppas, 1999):…”

Section: Swelling Experiments and Flory-rehner Calculationsmentioning

confidence: 99%

Photocrosslinked hyaluronic acid hydrogels: Natural, biodegradable tissue engineering scaffolds

Leach

Bivens

Patrick

et al. 2003

Biotech & Bioengineering

706

259

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“…The spherulite growth or crystallization of the P(L-2HB)/ P(D-2HB) stereocomplex is completed in a substantially shorter period of time as compared with those of pure P(L-2HB) and P(D-2HB). From the results reported for PLLA/PDLA blends, [16][17][18][19][20] it is expected that the resistance of P(L-2HB)/P(D-2HB) blends to hydrolytic and thermal degradation should be higher than those of pure P(L-2HB) and P(D-2HB). Moreover, optically pure P(2HB) can form a heterostereocomplex with non-substituted PLA having a configuration opposite to that of P(2HB), 22 whereas optically pure phenyl-substituted PLA is reported to have a higher intermolecular interaction with non-substituted PLA having a configuration opposite to that of phenyl-substituted PLA.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Stereocomplexation between PLLA and its enantiomer poly(D-lactide) (that is, poly(D-lactic acid) or PDLA) can yield biodegradable materials having superior mechanical performance and resistance to hydrolytic and thermal degradation relative to pure PLLA and PDLA. [16][17][18][19][20] Poly(2-hydroxybutyrate) (that is, poly(2-hydroxybutanoic acid) or P(2HB)) is a biodegradable polymer with the structure of a poly(lactide) (that is, poly(lactic acid) or PLA) in which methyl groups are substituted with ethyl groups. A stereocomplex can also be formed by blending substituted enantiomeric PLAs, that is, poly(L-2-hydroxybutyrate) [P(L-2HB)] and poly(D-2-hydroxybutyrate) (P (D-2HB)).…”

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confidence: 99%

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Crystallization and hydrolytic/thermal degradation of a novel stereocomplexationable blend of poly(L-2-hydroxybutyrate) and poly(D-2-hydroxybutyrate)

Tsuji

Okumura

2010

Polym J

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The maximum radial growth rate of spherulites of the novel stereocomplexationable blend of poly(L-2-hydroxybutyrate) (P(L-2HB)) and poly(D-2-hydroxybutyrate) (P(D-2HB)) was observed to be substantially higher than those of pure P(L-2HB) and P(D-2HB). The hydrolytic degradation rate of the P(L-2HB)/P(D-2HB) blend traced by gravimetry and gel permeation chromatography was significantly lower than those of pure P(L-2HB) and P(D-2HB); this indicated that the blend had higher resistance to hydrolytic degradation. Further, the thermal degradation rate of the P(L-2HB)/P(D-2HB) blend was retarded as compared with those of pure P(L-2HB) and P(D-2HB). The results obtained in the present study indicate that the intermolecular interaction between P(L-2HB) and P(D-2HB) chains having opposite configurations in the amorphous regions or in the molten state was higher than that between P(L-2HB) or P(D-2HB) chains with the same configurations. The information obtained in the present study should be very useful for designing and processing pure, biodegradable materials of P(L-2HB), P(D-2HB) and their blends for biomedical, pharmaceutical and environmental applications. Keywords: crystallization; hydrolytic degradation; poly(hydroxybutanoic acid); poly(hydroxybutyric acid); stereocomplex; thermal degradation INTRODUCTION Poly(L-lactide) (that is, poly(L-lactic acid) or PLLA) is a biodegradable polymer produced from plant-derived renewable resources and is now used for biomedical, pharmaceutical, environmental, industrial and commercial applications. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Stereocomplexation between PLLA and its enantiomer poly(D-lactide) (that is, poly(D-lactic acid) or PDLA) can yield biodegradable materials having superior mechanical performance and resistance to hydrolytic and thermal degradation relative to pure PLLA and PDLA. [16][17][18][19][20] Poly(2-hydroxybutyrate) (that is, poly(2-hydroxybutanoic acid) or P(2HB)) is a biodegradable polymer with the structure of a poly(lactide) (that is, poly(lactic acid) or PLA) in which methyl groups are substituted with ethyl groups. A stereocomplex can also be formed by blending substituted enantiomeric PLAs, that is, poly(L-2-hydroxybutyrate) [P(L-2HB)] and poly(D-2-hydroxybutyrate) (P (D-2HB)). 21 The melting temperature (T m ) of the P(L-2HB)/P(D-2HB) stereocomplex (ca. 200 1C) is higher than those of pure P(L-2HB) and P(D-2HB) (ca. 100 1C). The spherulite growth or crystallization of the P(L-2HB)/ P(D-2HB) stereocomplex is completed in a substantially shorter period of time as compared with those of pure P(L-2HB) and P(D-2HB). From the results reported for PLLA/PDLA blends, [16][17][18][19][20] it is expected that the resistance of P(L-2HB)/P(D-2HB) blends to hydrolytic and

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“…9,10 Due to these weak cross-linking mechanisms, most of the developed biodegradable hydrogels exhibit poor mechanical properties. 11,12 In contrast, synthetic chemically cross-linked hydrogels with strong covalent bonds present an enhanced mechanical strength.…”

Section: Introductionmentioning

confidence: 99%

Biodegradable HEMA‐based hydrogels with enhanced mechanical properties

Moghadam

Pioletti

2015

J Biomed Mater Res

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Hydrogels are widely used in the biomedical field. Their main purposes are either to deliver biological active agents or to temporarily fill a defect until they degrade and are followed by new host tissue formation. However, for this latter application, biodegradable hydrogels are usually not capable to sustain any significant load. The development of biodegradable hydrogels presenting load-bearing capabilities would open new possibilities to utilize this class of material in the biomedical field. In this work, an original formulation of biodegradable photo-crosslinked hydrogels based on hydroxyethyl methacrylate (HEMA) is presented. The hydrogels consist of short-length poly(2-hydroxyethyl methacrylate) (PHEMA) chains in a star shape structure, obtained by introducing a tetra-functional chain transfer agent in the backbone of the hydrogels. They are cross-linked with a biodegradable N,O-dimethacryloyl hydroxylamine (DMHA) molecule sensitive to hydrolytic cleavage. We characterized the degradation properties of these hydrogels submitted to mechanical loadings. We showed that the developed hydrogels undergo long-term degradation and specially meet the two essential requirements of a biodegradable hydrogel suitable for load bearing applications: enhanced mechanical properties and low molecular weight degradation products.

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Physically crosslinked dextran hydrogels by stereocomplex formation of lactic acid oligomers: degradation and protein release behavior

Cited by 194 publications

References 50 publications

Photocrosslinked hyaluronic acid hydrogels: Natural, biodegradable tissue engineering scaffolds

Photocrosslinked hyaluronic acid hydrogels: Natural, biodegradable tissue engineering scaffolds

Crystallization and hydrolytic/thermal degradation of a novel stereocomplexationable blend of poly(L-2-hydroxybutyrate) and poly(D-2-hydroxybutyrate)

Biodegradable HEMA‐based hydrogels with enhanced mechanical properties

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