Minocycline Hydrochloride Entrapped Biomimetic Nanofibrous Substitutes for Adipose-Derived Stem Cells Differentiation into Osteogenesis

Abstract

Hybrid biocomposite nanofibrous structures that mimics native extracellular matrix have been extensively applied for bone tissue engineering (BTE) due to their potential in efficiently inducing cellular response for the secretion of extracellular matrix (ECM). This study performed fabrication of uniform porous polycaprolactone (PCL), polycaprolactone/silk fibroin (PCL/SF), polycaprolactone/silk fibroin/minocycline hydrochloride (PCL/SF/MH), polycaprolactone/collagen (PCL/COL), and polycaprolactone/collagen/minocycline hydrochloride (PCL/COL/MH) biocomposites nanofibrous scaffolds by electrospinning, for comparing their properties to use in bone tissue regeneration. Field emission scanning electron microscopy (FESEM) images of fabricated nanofibrous scaffolds revealed porous, beadless, uniform fibers of diameter in the range of 147.13 ± 28.02 to 176.53 ± 22.34 nm and porosity around 82–93 %. Adipose-derived stem cells (ADSCs) considered as the novel cell therapeutics were cultured on these electrospun fibrous scaffolds to undergo osteogenic differentiation for BTE. The cell morphology, proliferation, and interactions were analyzed by CMFDA dye extrusion, MTS assay, and FESEM analysis, respectively. Differentiation of ADSCs into osteogenesis was determined by alkaline phosphatase activity, mineralization by alizarin red staining, and osteogenic protein expression by immunofluorescence analysis. The results demonstrated that the addition of SF and MH to PCL-based scaffolds improved the mechanical stability, interconnected pores, and surface roughness of the scaffolds initiating heightened biological functions such as ADSCs adhesion, proliferation, differentiation, and mineralization into osteogenesis for bone tissue regeneration. Globally, the rate of bone defects or trauma has been trending upwards and is predicted to rapidly increase by 2020. This is mainly due to the lack of physical activity, age, and increased obese populations. A basic understanding of the morphological characteristics and biological functions of mineralized bone tissue substrates is required for effective clinical treatments. The engineered bone tissue substrates have been potentially used as an alternative to the traditional bone grafts. However using these engineered bone substrates in clinical practices has certain limitations. These limitations can be overcome by the inclusion of natural polymers, growth factors, and stem cells. The current study demonstrates the addition of silk fibroin and minocycline hydrochloride to polycaprolactone-based scaffolds potentially enhanced adipose-derived stem cells differentiation into osteogenesis.