125 research outputs found
Cell delivery for regenerative medicine by using bioresorbable polymers
No full textFor regenerative medicine, the development of an optimal biomaterial system to deliver cells is crucial to precisely locate cells in the target site while preserving cell activity and function. In addition, the cell delivery construct should have the same instructive role as the extracellular microenvironment that naturally surrounds cells within a tissue. This chapter presents an overview of main concepts for the design of bioresorbable constructs for cell delivery and tissue regeneration, namely, types of polymers with recognized biocompatibility and bioresorbability, mechanical properties, structural architecture, and mass transport of the construct, as well as incorporation of biochemical and biophysical cues to provide instructive cell signaling and scaffold bioactivity. Regulatory and clinical aspects are mentioned at the end as they are important to ensure commercial success for these cutting-edge products
Electrospun nanofibrous scaffolds: potentialities and applications in tissue engineering
No full textDevelopment of artificial scaffolds for tissue engineering is a key area of research in the regenerative medicine field. In the in vivo microenvironment, mammalian cells are surrounded by a natural fibrillar extracellular matrix whose elements are typically organized in the nanometer scale. Progresses in nanothechnologies allowed to develop biomimetic nanofibrous scaffolds that were demonstrated to play a crucial role in controlling cell migration, proliferation, differentiation, and other complex tissue functions.
This presentation will focus on the design and application of nanofibrous scaffolds fabricated through the electrospinning technology, an increasingly popular process to produce non-woven textiles composed of fibres with diameters ranging from hundreds of nanometers to several tenths of microns. The great interest towards this technology arises from the simplicity of the set-up, the cost-effectiveness of the apparatus and versatility, that allows to produce electrospun materials possessing a wide range of chemical-physical properties. In addition, it is also possible to obtain fibres from polymer blends or drug-loaded and particle-loaded fibres as well as “composite” non-woven textiles by concomitantly electrospin different materials. Another interesting advantage of electrospinning is the possibility to tune mesh micro/nano-architecture - in terms of fibre dimension, fibre surface porosity and fibre orientation - by tuning process parameters. This presentation will give an overview of frontier-research on biomimetic electrospun scaffolds and will point out some of the current industrial applications, as well as future potentiality of electrospun scaffolds in the biomedical field
Analysis of new synthetic electrospun scaffolds for applications in skeletal muscle tissue engineering
No full textElectrospun nanofibers for enhancing structural performance of composite materials
No full text10.1002/pat.1837Polymers for Advanced Technologies223339-34
Laccase-Carrying Polylactic Acid Electrospun Fibers, Advantages and Limitations in Bio-Oxidation of Amines and Alcohols
No full textLaccases are oxidative enzymes that could be good candidates for the functionalization of biopolymers with several applications as biosensors for the determination of bioactive amine and alcohols, for bioremediation of industrial wastewater, and for greener catalysts in oxidation reactions in organic synthesis, especially used for non-phenolic compounds in combination with redox mediators in the so-called Laccase Mediator System (LMS). In this work, we describe the immobilization of Laccase from Trametes versicolor (LTv) in poly-L-lactic acid (PLLA) nanofibers and its application in LMS oxidation reactions. The PLLA-LTv catalysts were successfully produced by electrospinning of a water-in-oil emulsion with an optimized method. Different enzyme loadings (1.6, 3.2, and 5.1% (w)/(w)) were explored, and the obtained mats were thoroughly characterized. The actual amount of the enzyme in the fibers and the eventual enzyme leaching in different solvents were evaluated. Finally, the PLLA-LTv mats were successfully applied as such in the oxidation reaction of catechol, and in the LMS method with TEMPO as mediator in the oxidation of amines with the advantage of easier work-up procedures by the immobilized enzyme. However, the PLLA-LTv failed the oxidation of alcohols with respect to the free enzyme. A tentative explanation was provided
Biocotalysis provides polymers with a broad range of solid-state properties
No full textHigh molecular weight polymers that cannot be obtained by
chemical routes are easily synthesized by lipase-catalyzed polymerization. Some lipases such as Candida antarctica Lipase B, when used in ring opening polymerization, allow incorporation of different monomers along the chain leading to copolymers with defined composition and microstructure. Control over microstructure is critical to the ultimate goal of tailoring the physical, mechanical,
and biological properties of copolymers. Hydrophilic/hydrophobic
balance can be adjusted by a suitable choice of the two monomers
and of composition, leading to materials with tunable hydrolytic
degradation rate for environmental and biomedical applications.
Copolymers of omega-pentadecalactone with epsilon-caprolactone, valerolactone, dioxanone and trimethylenecarbonate are highly crystalline over the whole composition range, an unusual behavior due to co-crystallization of the co-monomer units. Copolyestercarbonates, copolyesteramides and polyol-containing copolyesters synthesized by lipase-catalysed polycondensation show strongly composition dependent physical properties, that can be easily tailored by composition control and cover the whole range from hard solid materials down to gluelike substances
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