Comparative Study of Single and Coaxial Electrospun Antimicrobial Cross-Linked Scaffolds Enriched with Aloe Vera: Characterization, Antimicrobial Activity, Drug Delivery, Cytotoxicity, and Cell Proliferation on Adipose Stem Cells and Human Skin Fibroblast

Abstract

The preparation of materials with application in the biomedical field needs to attend some characteristics such as biocompatibility, nontoxicity, adequate mechanical properties, and the ability to mimic the extracellular matrix. Scaffolds for use in cell culture were prepared based on gelatin, polylactic acid (PLA), aloe vera mucilage, and tetracycline. Fibers were prepared in single and coaxial configuration and then cross-linked with glutaraldehyde saturated vapor. The fibers were obtained with cylindric morphology and changed to ribbon morphology and porous membranes, similarly to the extracellular matrix, when cross-linked. Membranes prepared by coaxial electrospinning showed core− shell structures when observed by transversal images, which is beneficial for controlled drug release. Characterization techniques such as scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy demonstrated the cross-linking due to the increase in diameter, formation of imine groups, and improvement of thermal stability. Antibiotic release tests showed that the prevalent release mechanism is diffusion and can be controlled considering the encapsulation effect, when fibers are prepared with a coaxial configuration, increasing the drug release time, making it a suitable material for controlled release. The biological evaluation of the scaffolds was carried out in two cell lines: mammalian adipose stem cells (ASCs), used as a primary cell culture, and Detroit 548 human skin fibroblasts as a dermal cell model. Aloe vera enriched scaffolds showed better activity in contact with both cell lines, exhibiting cell viability values greater than 90% and favorable results in live−dead assays when no damaged cells were observed. Cell proliferation was evaluated using Detroit 548 human skin fibroblast on gelatin-based scaffolds by the staining of the adhered cells; the images showed good confluence and morphology of the cells on the aloe vera and antibiotic loaded membranes for both of the studied configurations. Antibiotic loaded membranes presented antimicrobial activity against S. aureus, and this behavior increased when aloe vera is included. According to the results, the scaffolds prepared on single configuration enriched with aloe vera and tetracycline could be used in dermal tissue engineering as burn dressings, diabetic foot apposite, and skin substitutes, and the scaffolds prepared with a coaxial configuration are recommended for controlled release systems of antibiotics as treatments for chronic wounds such as diabetic foot and burn healing.