A STUDY ON ANTIBACTERIAL PROPERTY OF HERBAL-BIOPOLYMER NANOENCAPSULATE TREATED FABRIC

The present study deals with the eco friendly antibacterial finish that has been integrated into bamboo/cotton woven treated fabric in the form of nanocapsules using ethanolic terminalia chebula, Rosmarinus officinalis and Opuntia littoralis (2:1:2) ratio and Chitosan biopolymer extracts  by exhaust method in order to reduce the bacterial growth on the fabric. This herbals-biopolymer extract was evaluated for activity against medically challenging bacteria such as Staphylococcus aureus and Escherichia coli. The in-vitro antibacteria were performed by AATCC 147 for the treated nanoencapsule coated sample. Then the coated sample was analyzed for morphology using FTIR, FESEM and Cytotoxicity test. Thus the study supports the concept of nano encapsulation providing better additional properties to bamboo/cotton fabric and the application of nanotechnology is one of the supreme ways for humanizing the antibacterial activity

Tailoring of processing parameters for sintering microsphere-based scaffolds with dense phase carbon dioxide

Jeon, J. H., Bhamidipati, M., Sridharan, B., Scurto, A. M., Berkland, C. J. and Detamore, M. S. (2013), Tailoring of processing parameters for sintering microsphere-based scaffolds with dense-phase carbon dioxide. J. Biomed. Mater. Res., 101B: 330–337. doi:10.1002/jbm.b.32843Microsphere-based polymeric tissue-engineered scaffolds offer the advantage of shape-specific constructs with excellent spatiotemporal control and interconnected porous structures. The use of these highly versatile scaffolds requires a method to sinter the discrete microspheres together into a cohesive network, typically with the use of heat or organic solvents. We previously introduced subcritical CO2 as a sintering method for microsphere-based scaffolds; here we further explored the effect of processing parameters. Gaseous or subcritical CO2 was used for making the scaffolds, and various pressures, ratios of lactic acid to glycolic acid in poly(lactic acid-co-glycolic acid), and amounts of NaCl particles were explored. By changing these parameters, scaffolds with different mechanical properties and morphologies were prepared. The preferred range of applied subcritical CO2 was 15–25 bar. Scaffolds prepared at 25 bar with lower lactic acid ratios and without NaCl particles had a higher stiffness, while the constructs made at 15 bar, lower glycolic acid content, and with salt granules had lower elastic moduli. Human umbilical cord mesenchymal stromal cells (hUCMSCs) seeded on the scaffolds demonstrated that cells penetrate the scaffolds and remain viable. Overall, the study demonstrated the dependence of the optimal CO2 sintering parameters on the polymer and conditions, and identified desirable CO2 processing parameters to employ in the sintering of microsphere-based scaffolds as a more benign alternative to heat-sintering or solvent-based sintering methods

Living Bacterial Sacrificial Porogens to Engineer Decellularized Porous Scaffolds

Decellularization and cellularization of organs have emerged as disruptive methods in tissue engineering and regenerative medicine. Porous hydrogel scaffolds have widespread applications in tissue engineering, regenerative medicine and drug discovery as viable tissue mimics. However, the existing hydrogel fabrication techniques suffer from limited control over pore interconnectivity, density and size, which leads to inefficient nutrient and oxygen transport to cells embedded in the scaffolds. Here, we demonstrated an innovative approach to develop a new platform for tissue engineered constructs using live bacteria as sacrificial porogens. E.coli were patterned and cultured in an interconnected three-dimensional (3D) hydrogel network. The growing bacteria created interconnected micropores and microchannels. Then, the scafold was decellularized, and bacteria were eliminated from the scaffold through lysing and washing steps. This 3D porous network method combined with bioprinting has the potential to be broadly applicable and compatible with tissue specific applications allowing seeding of stem cells and other cell types

Embryonic stem cell bioprinting for uniform and controlled size embryoid body formation

Embryonic stem cells (ESCs) are pluripotent with multilineage potential to differentiate into virtually all cell types in the organism and thus hold a great promise for cell therapy and regenerative medicine. In vitro differentiation of ESCs starts with a phase known as embryoid body (EB) formation. EB mimics the early stages of embryogenesis and plays an essential role in ESC differentiation in vitro. EB uniformity and size are critical parameters that directly influence the phenotype expression of ESCs. Various methods have been developed to form EBs, which involve natural aggregation of cells. However, challenges persist to form EBs with controlled size, shape, and uniformity in a reproducible manner. The current hanging-drop methods are labor intensive and time consuming. In this study, we report an approach to form controllable, uniform-sized EBs by integrating bioprinting technologies with the existing hanging-drop method. The approach presented here is simple, robust, and rapid. We present significantly enhanced EB size uniformity compared to the conventional manual hanging-drop method

Tissue engineering strategies for osteochondral repair

Tissue engineering strategies have been pushing forward several fields in the range of biomedical research. The musculoskeletal field is not an exception. In fact, tissue engineering has been a great asset in the development of new treatments for osteochondral lesions. Herein, we overview the recent developments in osteochondral tissue engineering. Currently, the treatments applied in a clinical scenario have shown some drawbacks given the difficulty in regenerate a fully functional hyaline cartilage. Among the different strategies designed for osteochondral regeneration, it is possible to identify cell-free strategies, scaffold-free strategies and advanced strategies, where different materials are combined with cells. Cell-free strategies consist in the development of scaffolds in the attempt to better fulfill the requirements of the cartilage regeneration process. For that, different structures have been designed, from monolayers to multi-layered structures with the intent to mimic the osteochondral architecture. In the case of scaffold-free strategies, they took advantage on the extracellular matrix produced by cells. The last strategy relies in the development of new biomaterials capable of mimicking the extracellular matrix. This way, the cell growth, proliferation and differentiation at the lesion site is expedited, exploiting the self-regenerative potential of cells and its interaction with biomolecules. Overall, despite the difficulties associated with each approach, tissue engineering has been proven a valuable tool in the regeneration of osteochondral lesions, and together with the latest advances in the field, promises to revolutionize personalized therapies.The authors thank the funds obtained through the Nanotech4als (ENMed/0008/2015), Hierarchitech (M-ERA-NET/0001/2014) and FROnTHERA (NORTE-01-0145-FEDER-0000232) projects. FRM acknowledges Portuguese Foundation for Science and Technology (FCT) for her post-doc grant (SFRH/BPD/117492/2016), MRC acknowledges Doctoral Program financed by Programa Operacional Regional do Norte, Fundo Social Europeu, Norte 2020 for her PhD grant (NORTE-08-5369-FSE-000044 TERM&SC), and JMO thanks FCT for the distinction attributed under the Investigator FCT program (IF/01285/2015).info:eu-repo/semantics/publishedVersio