Fabrication and characterization of P(3HB-co-4HB)/gelatine biomimetic nanofibrous scaffold for tissue engineering application

Fabrication and characterization of chlorhexidine gluconate loaded poly(vinyl alcohol)/45S5 nano-bioactive glass nanofibrous membrane for guided tissue regeneration applications

Polymeric barrier membranes are used in periodontal applications to prevent fibroblastic cell migration into the cavities of bone tissue and to properly guide the proliferation of tissues. In this study, the fabrication, characterization, bioactivity, and in vitro biological properties of polyvinyl alcohol-based nanofibrous membranes containing nano-sized 45S5 bioactive glass (BG) loaded with chlorhexidine (CH) gluconate with biocompatible, bioactive, and antibacterial properties for using as dental barrier membranes were investigated. Nanofibrous membranes with an average fiber diameter, pore size, and porosity of 210 nm, 24.73 μm, and 12.42%, respectively, were loaded with 1% and 2% CH, and the release profile was investigated. The presence of BG in the membranes promoted fibroblastic proliferation and the presence of CH provided antibacterial properties. Nanofibrous membranes exhibit a high ability to restrict bacterial growth while fulfilling the necessary conditions for use as a dental barrier thanks to their low swelling rates, significant surface bioactivities, and appropriate degradation levels.

Properties and structure of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) filaments for fused deposition modelling

Fused deposition modelling (FDM) is a process of additive manufacturing allowing creating of highly precise complex three-dimensional objects for a large range of applications. The principle of FDM is an extrusion of the molten filament and gradual deposition of layers and their solidification. Potential applications in pharmaceutical and medical fields require the development of biodegradable and biocompatible thermoplastics for the processing of filaments. In this work, the potential of production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) filaments for FDM was investigated in respect to its thermal stability. Copolymer P(3HB-co-4HB) was biosynthesised by Cupriavidus malaysiensis. Rheological and mechanical properties of the copolymer were modified by the addition of plasticizers or blending with poly(lactic acid). Thermal stability of mixtures was studied employing thermogravimetric analysis and rheological analyses by monitoring the time-dependent changes in the complex viscosity of melt samples. The plasticization of P(3HB-co-4HB) slightly hindered its thermal degradation but the best stabilization effect was found in case of the copolymer blended with poly(lactic acid). Overall, rheological, thermal and mechanical properties demonstrated that the plasticized P(3HB-co-4HB) is a potential candidate of biodegradable polymer for FDM processes.

Surface-Modified Highly Biocompatible Bacterial-poly(3-hydroxybutyrate-co-4-hydroxybutyrate): A Review on the Promising Next-Generation Biomaterial

Polyhydroxyalkanoates (PHAs) are bacteria derived bio-based polymers that are synthesised under limited conditions of nutritional elements with excess carbon sources. Among the members of PHAs, poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [(P(3HB-co-4HB)] emerges as an attractive biomaterial to be applied in medical applications owing to its desirable mechanical and physical properties, non-genotoxicity and biocompatibility eliciting appropriate host tissue responses. The tailorable physical and chemical properties and easy surface functionalisation of P(3HB-co-4HB) increase its practicality to be developed as functional medical substitutes. However, its applicability is sometimes limited due to its hydrophobic nature due to fewer bio-recognition sites. In this review, we demonstrate how surface modifications of PHAs, mainly P(3HB-co-4HB), will overcome these limitations and facilitate their use in diverse medical applications. The integration of nanotechnology has drastically enhanced the functionality of P(3HB-co-4HB) biomaterials for application in complex biological environments of the human body. The design of versatile P(3HB-co-4HB) materials with surface modifications promise a non-cytotoxic and biocompatible material without inducing severe inflammatory responses for enhanced effective alternatives in healthcare biotechnology. The enticing work carried out with P(3HB-co-4HB) promises to be one of the next-generation materials in biomedicines which will facilitate translation into the clinic in the future.

Biomimetic Hybrid Systems for Tissue Engineering

Tissue engineering approaches appear nowadays highly promising for the regeneration of injured/diseased tissues. Biomimetic scaffolds are continuously been developed to act as structural support for cell growth and proliferation as well as for the delivery of cells able to be differentiated, and also of bioactive molecules like growth factors and even signaling cues. The current research concerns materials employed to develop biological scaffolds with improved features as well as complex preparation techniques. In this work, hybrid systems based on natural polymers are discussed and the efforts focused to provide new polymers able to mimic proteins and DNA are extensively explained. Progress on the scaffold fabrication technique is mentioned, those processes based on solution and melt electrospinning or even on their combination being mainly discussed. Selection of the appropriate hybrid technology becomes vital to get optimal architecture to reasonably accomplish the final applications. Representative examples of the recent possibilities on tissue regeneration are finally given.