Fabrication and evaluation of multifunctional agarose based electrospun scaffolds for cutaneous wound repairs

Despite several advances in chronic wound management, natural product based scaffolds with high exude absorption and mechanical strength are still a hotspot in the medical field. Thus, present study illustrates the fabrication of agarose (AG; 10% w/v)/polyvinyl alcohol 12% w/v) based multifunctional nanofibrous electrospun scaffolds. Zinc citrate (1%, 3% and 5% w/w of the polymer) was used as a potential antibacterial agent. The fabricated scaffolds exhibit a swelling of ∼550% in phosphate buffer saline and mechanical strength of 10.11 ± 0.31 MPa which is suitable for most of the wound healing applications that require high strength. In vitro study revealed an increased migration and proliferation of L929 fibroblasts with AG blends when compared to the control. The fabricated scaffolds exhibited antibacterial properties against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacterial strains. Hence, a multifunctional (ability to protect wounds from bacterial infections along with effective swelling and mechanical support), natural product based, eco-friendly scaffold to serve as a potential wound dressing material has been successfully fabricated.

The combination of multi-functional ingredients-loaded hydrogels and three-dimensional printed porous titanium alloys for infective bone defect treatment

Biomaterial with the dual-functions of bone regeneration and antibacterial is a novel therapy for infective bone defects. Three-dimensional (3D)-printed porous titanium (pTi) benefits bone ingrowth, but its microporous structure conducive to bacteria reproduction. Herein, a multifunctional hydrogel was prepared from dynamic supramolecular assembly of sodium tetraborate (Na2B4O7), polyvinyl alcohol (PVA), silver nanoparticles (AgNPs) and tetraethyl orthosilicate (TEOS), and composited with pTi as an implant system. The pTi scaffolds have ideal pore size and porosity matching with bone, while the supramolecular hydrogel endows pTi scaffolds with antibacterial and biological activity. In vitro assessments indicated the 3D composite implant was biocompatible, promoted bone marrow mesenchymal stem cells (BMSCs) proliferation and osteogenic differentiation, and inhibited bacteria, simultaneously. In vivo experiments further demonstrated that the implant showed effective antibacterial ability while promoting bone regeneration. Besides distal femur defect, the innovative scaffolds may also serve as an ideal biomaterial (e.g. dental implants) for other contaminated defects.

An nMgO containing scaffold: Antibacterial activity, degradation properties and cell responses

Bone repair failure caused by implant-related infections is a common and troublesome problem. In this study, an antibacterial scaffold was developed via selective laser sintering with incorporating nano magnesium oxide (nMgO) to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The results indicated the scaffold exerted high antibacterial activity. The antibacterial mechanism was that nMgO could cause oxidative damage and mechanical damage to bacteria through the production of reactive oxygen species (ROS) and direct contact action, respectively, which resulted in the damage of their structures and functions. Besides, nMgO significantly increased the compressive properties of the scaffold including strength and modulus, due to its excellent mechanical properties and uniform dispersion in the PHBV matrix. Moreover, the degradation tests indicated nMgO neutralized the acid degradation products of PHBV and benefited the degradation of the scaffold. The cell culture demonstrated that nMgO promoted the cellular adhesion and proliferation, as well as osteogenic differentiation. The present work may open the door to exploring nMgO as a promising antibacterial material for tissue engineering.