Porous chitosan-gelatin scaffolds embedded with PLGA nanoparticles for bone repair.

Bone regeneration can be accelerated by localized delivery of appropriate growth factors/bio active molecules. Localized delivery can be achieved by incorporating bioactive molecules within biodegradable particulate carrier system followed by embed them in a suitable porous scaffolds. These carrier system facilitates the impregnated growth factor(s) to release at a desirable rate and concentration, and to linger at injury sites for a sufficient time to recruit progenitors and stimulate tissue healing processes. In this study, an attempt has been made to engraft the porous chitosan-gelatin scaffolds with PLGA nanoparticles for localized delivery of bioactive components. Scaffolds loaded with PLGA nanoparticles were subjected to physical and mechanical characterizations such as microarchitecture analysis, swelling, porosity, mechanical properties, dissolution studies

Biomaterials of natural origin in regenerative medicine

Biodegradable polymers have been used for various applications where the short-lived existence of materials is required and they find applications as sutures, scaffolds for tissue regeneration, tissue adhesives, and transient barriers for tissue adhesion, as well as drug delivery systems. This chapter deals with the most commonly used natural polymers for regenerative medicine. It also presents some examples of commercially available natural-origin materials. Natural polymers are widely used due to their similarities with the extracellular matrix (ECM), the variety of physico-chemical properties, the generally high biological performance and the cell or enzyme-controlled degrad-ability. These characteristics classify the natural-origin polymers as one of the most attractive materials to be used in the tissue engineering field and drug delivery application. The fields of tissue engineering and regenerative medicine aim to promote the regeneration of tissues or replacing failing or malfunctioning organs, by means of combining a scaffold/support material, adequate cells and bioactive molecules. Different materials have been proposed to be used as both three-dimensional porous scaffolds and hydrogel matrices for distinct tissue engineering strategies. Among them, polymers of natural origin are one of the most attractive options. In the following pages, the most studied, promising and recently proposed naturally derived polymers for tissue engineering applications are described. Different classes of such type of polymers and their blends with other polymers are emphasized, with special focus on polysaccharides and proteins. The adaptation of conventional methods or non-conventional processing techniques for processing scaffolds from natural origin based polymers is described. The use of particles, membranes and injectable systems based on this kind of materials is also overviewed, especially for what concerns the present status of the research that should lead towards their final application. Finally, the biological performance of tissue engineering constructs based on natural-based polymers is discussed chronologically, using several examples for different clinically relevant application

Influence of parathyroid hormone-loaded plga nanoparticles in porous scaffolds for bone regeneration

Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds