RESUMO
Poly(ε-caprolactone) (PCL) is commonly used in devices for tissue reconstruction due to its biocompatibility and suitable mechanical properties. However, its high crystallinity and hydrophobicity do not favor cell adhesion and difficult polymer bioresorption. To improve these characteristics, the development of engineered scaffolds for tissue regeneration, based on poly(globalide-co-ε-caprolactone) (PGlCL) covalently bonded with N-acetylcysteine (PGlCL-NAC) was proposed. The scaffolds were obtained from polymer blends of PCL and PGlCL-NAC, using the electrospinning technique. The use of PGlCL-NAC allowed for the modification of the physical and chemical properties of PCL electrospun scaffolds, including an expressive reduction in the fiber's diameter, hydrophobicity, and crystallinity. All electrospun scaffolds showed no cytotoxicity against fibroblasts (McCoy cells). In vitro biocompatibility assays showed that all tested scaffolds provided high cell viability and proliferation in short-term (NRU, MTT, and nuclear morphology assays) and long-term (clonogenic assay) assays. Nevertheless, PGlCL-NAC based scaffolds have favored the survival and proliferation of the cells in comparison to PCL scaffolds. Cell adhesion on the scaffolds assessed by electronic microscopy images confirmed this behavior. These results suggest that the incorporation of PGlCL-NAC in scaffolds for tissue regeneration could be a promising strategy to improve cell-surface interactions and contribute to the development of more efficiently engineered biomedical devices.
Assuntos
Acetilcisteína/química , Caproatos/metabolismo , Fibroblastos/metabolismo , Lactonas/metabolismo , Poliésteres/química , Engenharia Tecidual/métodosRESUMO
The demand for environmentally friendly products allied with the depletion of natural resources has increased the search for sustainable materials in chemical and pharmaceutical industries. Polyesters are among the most widely used biodegradable polymers in biomedical applications. In this work, aliphatic polyesters (from globalide and ω-pentadecalactone) were synthesized using a new commercial biocatalyst, the low-cost immobilized NS 88011 lipase (lipase B from Candida antarctica immobilized on a hydrophobic support). Results were compared with those obtained under the same conditions using a traditional, but more expensive, commercial biocatalyst, Novozym 435 (lipase B from C. antarctica immobilized on Lewatit VP OC). When NS 88011 was used in the polymerization of globalide, longer reaction times (240 min)-when compared to Novozym 435-were required to obtain high yields (80-90 wt%). However, higher molecular weights were achieved. When poly(ω-pentadecalactone) was synthesized, high yields and molecular weights (130,000 g mol-1) were obtained and the enzyme concentration showed strong influence on the polyester properties. This is the first report describing NS 88011 in polymer synthesis. The use of this cheaper enzymatic preparation can provide an alternative for polyester synthesis via enzymatic ring-opening polymerization.