Global challenges in scaffolds technology offer opportunities for further research that involves new types of polymers in different forms such as films, membranes, and beads. In the last decades, natural polymers have been investigated to be used as cell scaffolds [1]. However, to be successfully used these materials should be modified to improve different properties, such as in-vivo stability, biocompatibility, biodegradability, and potential interaction with cells. For that, the scaffolds should also have a cell-friendly surface, and interconnected pores for the transport of cells, nutrients, and metabolites [2].One of the most promising materials to be used as cell scaffolds, among other applications in biomedicine is silk fibroin (SF), which is a biodegradable polymer, and biocompatible with human tissues. Its chemical composition consists of simple amino acids, such as glycine, alanine, serine, and tyrosine [3,4]. SF is a molecule with high tensile strength, elasticity, and resilience. It has been used in diverse applications, such as hydrogels synthesis, supports for enzymes immobilization, drug delivery, and etc. [3,5,6]. Konjac glucomannan (KGM) is also a biodegradable and biocompatible material [1]. Its chemical structure is composed of d-mannose and d-glucose monomers linked by β(1→4) bonds. KGM is a hydrophilic polymer with high viscoelasticity and mechanical resistance. Over the last years, it was mainly used as a bioactive polymer. KGM, combined with other polymers, can be used as a controlled delivery system for drugs, and antimicrobial materials [7,8].In spite of the mentioned properties of SF and KGM, their mechanical properties could be improved in order to be used as a scaffold. Blending two or more polymers is a usual technique to overcome challenges in polymer properties and resulting in the new materials. Several studies of SF-based blends have been reported in the literature. Park et al. (1999) verified that the mechanical tensile strength of SF and chitosan (CHI) membranes depended on CHI concentration. Moreover, the resistance of membranes presented higher value than pure polymers, due to the increase in β-sheet conformational transition [9]. Kweon et al. (2001) studied films of SF and CHI to understand the effect of fibroin and chitosan ratio on the physical characteristics of blends. They verified that the mechanical properties the films were improved when blends were formed with 10–40% chitosan [10]. Lee et al. (2004) studied the physical and structural properties of SF and sodium alginate blends and concluded that the structural characteristics of SF in blends were not affected by the incorporation of sodium alginate. Also, the mechanical properties of these blends were improved because sodium alginate is a hard polysaccharide [11]. She et al. (2008) reported that the mechanical properties of SF/CHI scaffolds could be controlled by adjusting their composition [12].In that sense, this study was focused on the synthesizes and characterization of porous blend beads obtained from two natural polymers, SF and KGM, with suitable characteristics to be applied to tissue engineering or drug release field [13]. A surface morphological analysis was performed by scanning electron microscope (SEM), physicochemical characterizations were obtained by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TGA), and X-ray diffraction (XDR), and a validation of mechanical resistance was performed using compression tests. Finally, cytocompatibility assays were carried out using two kinds of cell lines: human keratinocytes (HaCaT) and murine fibroblast (BALB/c 3T3).
https://www.mdpi.com/2073-4360/10/8/923/htm
Carla Giometti França, Daisy Machado, Jacobo Hernandez-Montelongo, Marcelo Lancellotti, Marisa Masumi Beppu, Vicente Franco Nascimento
