Bioactive polymeric scaffolds for tissue engineering

A variety of engineered scaffolds have been created for tissue engineering using polymers,ceramics and their composites.Biomimicry has been adopted for majority of the three-dimensional(3D)scaffold design both in terms of physicochemical properties,as well as bioactivity for superior tissue regeneration.Scaffolds fabricated via salt leaching,particle sintering,hydrogels and lithography have been successful in promoting cell growth in vitro and tissue regeneration in vivo.Scaffold systems derived from decellularization of whole organs or tissues has been popular due to their assured biocompatibility and bioactivity.Traditional scaffold fabrication techniques often failed to create intricate structures with greater resolution,not reproducible and involved multiple steps.The 3D printing technology overcome several limitations of the traditional techniques and made it easier to adopt several thermoplastics and hydrogels to create micro-nanostructured scaffolds and devices for tissue engineering and drug delivery.This review highlights scaffold fabrication methodologies with a focus on optimizing scaffold performance through the matrix pores,bioactivity and degradation rate to enable tissue regeneration.Review highlights few examples of bioactive scaffold mediated nerve,muscle,tendon/ligament and bone regeneration.Regardless of the efforts required for optimization,a shift in 3D scaffold uses from the laboratory into everyday life is expected in the near future as some of the methods discussed in this review become more streamlined.

Studies of nanoparticle delivery with in vitro bio-engineered microtissues

A variety of engineered nanoparticles,including lipid nanoparticles,polymer nanoparticles,gold nanoparticles,and biomimetic nanoparticles,have been studied as delivery vehicles for biomedical applications.When assessing the efficacy of a nanoparticle-based delivery system,in vitro testing with a model delivery system is crucial because it allows for real-time,in situ quantitative transport analysis,which is often difficult with in vivo animal models.The advent of tissue engineering has offered methods to create experimental models that can closely mimic the 3D microenvironment in the human body.This review paper overviews the types of nanoparticle vehicles,their application areas,and the design strategies to improve delivery efficiency,followed by the uses of engineered microtissues and methods of analysis.In particular,this review highlights studies on multicellular spheroids and other 3D tissue engineering approaches for cancer drug development.The use of bio-engineered tissues can potentially provide low-cost,high-throughput,and quantitative experimental platforms for the development of nanoparticle-based delivery systems.