Poly(ethylene-co-vinylalcohol)/Poly(δ-valerolactone)/Aspirin Composite: Model for a New Drug-Carrier System

Abstract

The release dynamics of aspirin(ASP), used as a drug model, from the poly(ethylene-co-vinyl alcohol)/poly(δ-valerolactone) (PE-co-VAL/Pδ-VL) hydrogel blend was controlled by varying the blend’s degree of swelling through a gradual loading of Pδ-VL (hydrophobic polymer) in this copolymer matrix. To achieve this goal, a series of PE-co-VAL/Pδ-VL blends with different ratios was prepared through the solvent casting method, and the miscibility of this polymer blend was evaluated by using Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and scanning electronic microscopy methods. The tests of cell adhesion and growth on the PE-co-VAL/Pδ-VL specimens were performed using the 3-(4,5-demethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and the results obtained were the best performance in terms of cell viability, cell adhesion, and growth of the PE-co-VAL/Pδ-VL50 material. The dynamic mechanical properties of the prepared material were also examined by dynamic mechanical analysis; the results obtained showed a material having intermediary mechanical properties between those of the two components. On the basis of these characterizations, the blend showing the best performance, such as the PE-co-VAL/Pδ-VL50 system, was chosen as a carrier to study the in vitro control of the release dynamics of ASP from the ASP/PE-co-VAL/Pδ-VL drug-carrier system when administered orally, in which the influences of the ASP content and the degree of swelling of the PE-co-VAL/Pδ-VL blend were investigated. Based on the data obtained and the gastrointestinal transit time reported by Beltzer et al., it was possible to estimate the distribution of the in vitro cumulative ASP released in different digestive system organs regardless of the actions of any enzymes and microorganisms and select the best-performing drug-carrier system.

Poly(δ-valerolactone)/Poly(ethylene-co-vinylalcohol)/β-Tricalcium Phosphate Composite as Scaffolds: Preparation, Properties, and In Vitro Amoxicillin Release

“…This copolymer is synthesized by various processes, the most important of which is ethylene’s copolymerization with vinyl acetate, which produces poly(ethylene-co-vinylacetate) followed by hydrolysis of the vinyl alcohol units [ 24 ]. Being one of the most popular and flexible materials, PEVAL is largely investigated to be used in the biomedical field, notably as a carrier in the drug delivery field because of good blood compatibility [ 25 ], high gas-barrier [ 26 ], biocompatibility [ 25 ], harmlessness toward health [ 27 ], non-toxicity [ 28 ], hydrophilicity, availability of ethylene units to control its ability to swell and hence control the rate of its delivery [ 29 ], and has safe ethylene units liable to degradation and can undergo complete biodegradation, notably in the presence of enzymes [ 28 , 30 ].…”

Low-Temperature and Solventless Ring-Opening Polymerization of Eutectic Mixtures of l-Lactide and Lactones for Biodegradable Polyesters

“…Early degradation was reported to take place on the surface, as could be observed in the PLLA N –PVAL sample in Figure S15 in the Supporting Information, where after 28 days, the diameter decreased, as did the pH of the solution from 7.4 to 2.8 due to the acidic nature of the released by-products of degradation. The degradation characteristics of polyesters could be applied in areas that require short-term degradation profiles in acidic media, such as drug delivery systems or the release of special cargos in the agroindustry. ,,− …”

“…These obtained polyesters presented semicrystalline behavior, as observed by XRD, showing the characteristic peaks of PLLA at 2θ values of 16 and 19°, of PCL at 21.4 and 23.8°, and of PVL at 21.7 and 24.11°(Figure S11 in the Supporting Information). 31 Figure 5 shows that the crystallinity of the resulting PLLA is slightly favored when using DBN for the ROP of LLA 30 −CL 70 (Figure 5a), which is greater for the ROP of LLA 30 −VAL 70 . As discussed previously, although the polymerization of LLA in both systems (PLLA U −PCL and PLLA N −PCL) reached complete conversions within minutes, slightly lower kinetics in the case of DBN may have allowed the rearrangement of PLLA chains and thus increased its crystallinity (see Figure 3d).…”

Bone Regeneration Using PEVAV/β-Tricalcium Phosphate Composite Scaffolds in Standardized Calvarial Defects: Micro-Computed Tomographic Experiment in Rats

“…PEVAV polymer blend have been recently synthesized and tested only once as drug carrier system [ 13 , 35 ]. Up to our knowledge, it has never been added to any synthetic graft material nor been assessed for bone regeneration.…”