Enzyme-catalyzed degradation of poly(l-lactide)/poly(ɛ-caprolactone) diblock, triblock and four-armed copolymers

Feng, Lijuan; Zhao, Zhenxian; Yang, Jian; Jia, Wei; Li, Suming

doi:10.1016/j.polymdegradstab.2008.10.023

Cited by 27 publications

(10 citation statements)

References 28 publications

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“…For example, Huang et al 51 studied the degradation of a PLA-PCL-PLA triblock polymer in phosphate buffer solution (PBS). Other authors have used different enzyme solutions such as lipase 52 or proteinase, 53 as well as in the presence of microorganisms 54 to determine the degradation kinetics of materials. We used DMEM + FBS because we believe this medium is more representative of physiological conditions than with lipase or PBS.…”

Section: Fernández Et Almentioning

confidence: 99%

Fumarate/Ceramic Composite Based Scaffolds for Tissue Engineering: Evaluation of Hydrophylicity, Degradability, Toxicity and Biocompatibility

Fernández¹,

Cortizo²,

Cortizo³

2014

j biomater tissue eng

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The present study was designed to investigate the possible cytotoxicity and biocompatibility of scaffolds based on previously characterized polymeric materials including poly--caprolactone (PCL) or polydiisopropyl fumarate (blended or on their own), with or without hydroxyapatite (HAP). Water contact angle was also evaluated to determine the hydrophylicity of each scaffold. Degradation of different scaffolds was evaluated after a 10-week incubation in Dulbecco's modified eagle medium (DMEM) supplemented with 5% (v/v) fetal bovine serum (FBS). Bone Marrow Stromal Cells (MSC) were grown on different scaffolds in an osteogenic medium, after which alkaline phosphatase activity (ALP) was evaluated. ALP activity increased when MSC were grown on PCL + HAP or Blend + HAP, as compared to PCL or Blend without HAP. The effect of different scaffolds on the proliferation of the macrophage cell line RAW 264.7, production of nitric oxide (NO) and secretion of pro-inflammatory cytokines was examined. After 72 h, macrophages proliferated equally well on all scaffolds, maintaining a rounded morphology. None of the investigated scaffolds induced production of NO or cytokine release into the culture media, suggesting an absence of cytotoxicity. Therefore, these polymer-and HAP-based scaffolds could potentially be used as bone substitute materials.

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Section: Fernández Et Almentioning

confidence: 99%

Fumarate/Ceramic Composite Based Scaffolds for Tissue Engineering: Evaluation of Hydrophylicity, Degradability, Toxicity and Biocompatibility

Fernández¹,

Cortizo²,

Cortizo³

2014

j biomater tissue eng

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“…So, use of copolymers instead of homopolymers can be more useful in improving the physico‐mechanical properties of the bionanocomposite. To improve thermal resistance, crystallization of poly( d , l ‐lactide), nanolamellar biodegradable triblock using DLL as terminal segment, and DV as middle segment was synthesized earlier from this laboratory . Copolymerization of DLL with DV increased the percentage crystallinity, decreased the glass transition temperature, and thereby reduced the chance of thermal degradation during processing.…”

Section: Introductionmentioning

confidence: 99%

Sustainable bionanocomposite from d,l‐lactide/δ‐valerolactone triblock and bionanowhiskers: Preparation, characterization, and properties

Kasyapi

Kumar

Bhowmick

2017

J of Applied Polymer Sci

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Bionanocomposites were prepared using D,L-lactide-d-valerolactone-D,L-lactide triblock and unmodified and modified cellulose nanowhiskers (CNs) at different loadings (0, 2, 4, 8 wt %). Poly(d-valerolactone) chains were grafted on CNs for modification. These were characterized by various techniques. The broadening of OH (hydroxyl) stretching region and the presence of low-intensity peaks at 1064 cm 21 for CAO/CAC stretching vibration and 1426 cm 21 for bending vibration of CH 2 group , were evident in Fourier transform infrared spectra of the nanocomposites. The increase in crystallinity was noticed as the amount of nanowhiskers was increased. The nanowhiskers having the width in the range of 80-300 nm were uniformly dispersed in the triblock matrix. The tensile strength and modulus increased by 130% and 50% respectively at 8 wt % of filler loading. The storage modulus, loss modulus, complex viscosity, and tan d values increased with increased filler loading. Further improvement in mechanical properties was observed with the modified CNs. The modulus mapping from atomic force microscopy confirmed the effective reinforcement behavior of the nanowhiskers. Scaffold fabrication using the bionanocomposite exhibited porous nature, having a homogeneous dispersion of CNs on the surface of the scaffold. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay confirmed the suitability of the composite material for scaffold application.Till date, different polymer matrices have been investigated to prepare cellulose-based bionanocomposite. 17-21 Free sulfate groups were introduced on the surface of CNs by sulfuric acid hydrolysis. 22 These negative charges facilitated the formation of Additional Supporting Information may be found in the online version of this article.

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“…13 However, poor elasticity and low drug permeability of polylactides lead to its copolymerization with glycolides or lactones, especially ε-caprolactone. 6,14,15 Block copolymers of lactide and glycolide-poly lactide-coglycolide (PLGA) are used in drug delivery systems in the form of microspheres, nanospheres, and nanofibers. 11,16,17 High rate of degradability owing to lactide and glycolide blocks and good cell adhesion makes them suitable for bioapplications.…”

Section: ■ Introductionmentioning

confidence: 99%

Raman and NMR Spectroscopic Studies on Hydrolytic Degradation of d,l-Lactide−δ-Valerolactone–d,l-Lactide Copolymer

Kasyapi¹,

Mehta²,

Bhowmick

2015

ACS Sustainable Chem. Eng.

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Hydrolytic degradation of BAB terpolymers with δ-valerolactone as the central (A) block and D,L-lactide as the terminal (B) block was studied by 1 H NMR and Raman spectroscopic techniques. The following variations were investigated: (i) the ratio of δ-valerolactone to D,Llactide, (ii) replacement of D,L-lactide with cis-lactide or glycolide, keeping A constant, and (iii) replacement of δ-valerolactone with ε-caprolactone, keeping B constant. The intensity of the characteristic peaks for the D,Llactide segment almost disappeared, and the intensity of the characteristic signals for δ-valerolactone decreased after 30 days. As evident from quantitative analysis of 1 H NMR, 97% of the D,L-lactide segment degraded within 30 days, and the value was 35% for the δ-valerolactone block (both based on the initial value). Upon degradation of the triblock, a significant increase in water uptake and decrease in molecular weight and bulk weight were observed. Crystallinity of the triblock increased after degradation due to removal of the amorphous D,L-lactide from the system. An enormous increase in the ΔH m value after degradation was observed, supporting the increase in crystallinity. Replacing the middle segment with ε-caprolactone resulted in only 0.64% degradation of the middle segment in 30 days. The degradation of terminal segment was reduced using cis-lactide or glycolide in place of D,L-lactide. The disappearance of Raman signal at 870 cm −1 assigned for υC−COO stretching of DLL segment along with a decrease in CO stretching region (1725 cm −1 ) indicated cleavage of the ester linkages. Lower biodegradability of the triblock containing ε-caprolactone was also apparent from 29% degradation in the CO region compared to 55% degradation for the triblock with δ-valerolactone. Strong peaks at 1776, 1247, and 996 cm −1 were observed after 30 days due to remaining crystalline domains of polyglycolide in the triblock.

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Enzyme-catalyzed degradation of poly(l-lactide)/poly(ɛ-caprolactone) diblock, triblock and four-armed copolymers

Cited by 27 publications

References 28 publications

Fumarate/Ceramic Composite Based Scaffolds for Tissue Engineering: Evaluation of Hydrophylicity, Degradability, Toxicity and Biocompatibility

Fumarate/Ceramic Composite Based Scaffolds for Tissue Engineering: Evaluation of Hydrophylicity, Degradability, Toxicity and Biocompatibility

Sustainable bionanocomposite from d,l‐lactide/δ‐valerolactone triblock and bionanowhiskers: Preparation, characterization, and properties

Raman and NMR Spectroscopic Studies on Hydrolytic Degradation of d,l-Lactide−δ-Valerolactone–d,l-Lactide Copolymer

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