Cellulose is the most abundant polysaccharide on Earth. It can be obtained from a vast number of sources,e.g.cell walls of wood and plants, some species of bacteria, and algae, as well as tunicates, which are the only known cellulose-containing animals. This inherent abundance naturally paves the way for discovering new applications for this versatile material. This review provides an extensive survey on cellulose and its derivatives, their structural and biochemical properties, with an overview of applications in tissue engineering, wound dressing, and drug delivery systems. Based on the available means of selecting the physical features, dimensions, and shapes, cellulose exists in the morphological forms of fiber, microfibril/nanofibril, and micro/nanocrystalline cellulose. These different cellulosic particle types arise due to the inherent diversity among the source of organic materials or due to the specific conditions of biosynthesis and processing that determine the consequent geometry and dimension of cellulosic particles. These different cellulosic particles, as building blocks, produce materials of different microstructures and properties, which are needed for numerous biomedical applications. Despite having great potential for applications in various fields, the extensive use of cellulose has been mainly limited to industrial use, with less early interest towards the biomedical field. Therefore, this review highlights recent developments in the preparation methods of cellulose and its derivatives that create novel properties benefiting appropriate biomedical applications.

In this study, the interface-modified ternary blends based on polylactic acid/starch/polycaprolactone were prepared via melt blending. On one hand, the addition of triclosan-loaded polylactic acid (LATC30) nanoparticles imparted antibacterial properties to the blend, and on the other hand, the interfacial affinity between hydrophilic starch and hydrophobic polyesters was improved by establishing interactions between –Cl groups of triclosan and ester groups of PCL. AFM and rheological results demonstrated that the starch particles are very coarse in PLA/starch 50:50 (PLAS50) but as the content of PCL increased, the extent of chemical interactions between starch and PCL was increased which resulted in a much better dispersion and homogeneity of starch within the ternary blends. Tensile analysis indicated that the interface modification of starch by the hydrophobic PCL and triclosan significantly improved the elongation at break and tensile strength values of PLAS50, and the mechanical character of blends was transformed from brittle to ductile. Biodegradability was also investigated and the triclosan release rate was tuned, while the blends are also antibacterial and their cell-viability was approved. Overall, the ternary blending approach of PLA/starch/PCL using triclosan is a promising technique to extend the property range of PLA suitable for many medical applications.