Effect of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) surface with different wettability on fibroblast behavior

Bioengineered neo-corneal endothelium using collagen type-I coated silk fibroin film

Corneal transplantation, a common surgical protocol for visual acuity improvement, is limited owing to shortage of high quality donor corneas and/or lack of accurate replication of structural and biochemical composition of native cornea in a scaffold. Construction of neo-corneas utilizing novel, biocompatible and biodegradable scaffold/film source, could possibly address such formidable challenges. Herein, we designed optically transparent, micro-structurally stable silk films surface-coated with collagen type-I (Col-I/SF) as an alternative scaffold source for bioengineering of neo-cornea. Morphological, structural characteristics and in vitro biological studies were performed using primary rabbit corneal endothelial cells (rCEnCs) as models. The Col-I/SF films demonstrated higher Ra (nm) values compared to the bare SF surfaces. In vitro biological studies showed a significant increment in initial cell attachment and proliferation of cultured rCEnCs on the Col-I/SF films with well-maintained characteristic polygonal shape of rCEnCs. Although any remarkable changes regarding the morphology, expression of ZO-1 and Na(+)/K(+)-ATPase were absent, however the cells were found to be capable of well-expressing their functional proteins which regulates functions of corneal endothelium. Collectively, these results strongly suggest Col-I/SF film for future corneal transplantation therapy.

Polímeros biorreabsorvíveis como substrato para cultura de células e engenharia tecidual

Biomateriais poliméricos são desenvolvidos para uso como substitutos de tecidos danificados e/ou estimular sua regeneração. Uma classe de biomateriais poliméricos são os biorreabsorvíveis, compostos que se decompõem tanto in vitro quanto in vivo. São empregados em tecidos que necessitam de um suporte temporário para sua recomposição tecidual. Dentre os vários polímeros biorreabsorvíveis, destacam-se os alfa-hidróxi ácidos, entre eles, diferentes composições do poli(ácido lático) (PLA), como o poli(L-ácido lático) (PLLA), poli(D-ácido lático) (PDLA), poli(DL-ácido lático) (PDLLA), além do poli(ácido glicólico) (PGA) e da policaprolactona (PCL). Estes polímeros são considerados biorreabsorvíveis por apresentarem boa biocompatibilidade e os produtos de sua decomposição serem eliminados do corpo por vias metabólicas. Diversas linhas de pesquisa mostram que os diferentes substratos à base de PLA estudados não apresentam toxicidade, uma vez que as células são capazes de crescer e proliferar sobre eles. Além disso, diversos tipos de células cultivadas sobre diferentes formas de PLA são capazes de se diferenciarem sobre os diferentes polímeros e passar a produzir componentes de matriz extracelular. Neste trabalho, é revisada a utilização de substratos à base de alfa-hidróxi ácidos, com destaque para diferentes formas de PLA, utilizados como substratos para cultura de células, bem como suas aplicações.

Response of MG63 osteoblast-like cells onto polycarbonate membrane surfaces with different micropore sizes

Response of different types of cells on materials is important for the applications of tissue engineering and regenerative medicine. It is recognized that the behavior of the cell adhesion, proliferation, and differentiation on materials depends largely on surface characteristics such as wettability, chemistry, charge, rigidity, and roughness. In this study, we examined the behavior of MG63 osteoblast-like cells cultured on a polycarbonate (PC) membrane surfaces with different micropore sizes (0.2-8.0 microm in diameter). Cell adhesion and proliferation to the PC membrane surfaces were determined by cell counting and MTT assay. The effect of surface micropore on the MG63 cells was evaluated by cell morphology, protein content, and alkaline phosphatase (ALP) specific activity. It seems that the cell adhesion and proliferation were progressively inhibited as the PC membranes had micropores with increasing size, probably due to surface discontinuities produced by track-etched pores. Increasing micropore size of the PC membrane results in improved protein synthesis and ALP specific activity in isolated cells. There was a statistically significant difference (P<0.05) between different micropore sizes. The MG63 cells also maintained their phenotype under conditions that support a round cell shape. RT-PCR analysis further confirmed the osteogenic phenotype of the MG63 cells onto the PC membranes with different micropore sizes. In results, as micropore size is getting larger, cell number is reduced and cell differentiation and matrix production is increased. This study demonstrated that the surface topography plays an important role for phenotypic expression of the MG63 osteoblast-like cells.