Chapter 34 - Biocompatibility of nanocellulose: Emerging biomedical applications

Nanocellulose already proved to be a highly relevant material for biomedical applications, ensued by its outstanding mechanical properties and, more importantly, its biocompatibility. Nevertheless, despite their previous intensive research, a notable number of emerging applications are still being developed. Interestingly, this drive is not solely based on the nanocellulose features, but also heavily dependent on sustainability. The three core nanocelluloses encompass cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC). All these different types of nanocellulose display highly interesting biomedical properties per se, after modification and when used in composite formulations. Novel applications that use nanocellulose includewell-known areas, namely, wound dressings, implants, indwelling medical devices, scaffolds, and novel printed scaffolds. Their cytotoxicity and biocompatibility using recent methodologies are thoroughly analyzed to reinforce their near future applicability. By analyzing the pristine core nanocellulose, none display cytotoxicity. However, CNF has the highest potential to fail long-term biocompatibility since it tends to trigger inflammation. On the other hand, neverdried BNC displays a remarkable biocompatibility. Despite this, all nanocelluloses clearly represent a flag bearer of future superior biomaterials, being elite materials in the urgent replacement of our petrochemical dependence

Nanomedicine Formulations Based on PLGA Nanoparticles for Diagnosis, Monitoring and Treatment of Disease: From Bench to Bedside

Nanomedicine is among the most promising emerging fields that can provide innovative and radical solutions to unmet needs in pharmaceutical formulation development. Encapsulation of active pharmaceutical ingredients within nano-size carriers offers several benefits, namely, protection of the therapeutic agents from degradation, their increased solubility and bioavailability, improved pharmacokinetics, reduced toxicity, enhanced therapeutic efficacy, decreased drug immunogenicity, targeted delivery, and simultaneous imaging and treatment options with a single system.Poly(lactide-co-glycolide) (PLGA) is one of the most commonly used polymers in nanomedicine formulations due to its excellent biocompatibility, tunable degradation characteristics, and high versatility. Furthermore, PLGA is approved by the European Medicines Agency (EMA) and the Food and Drug Administration (FDA) for use in pharmaceutical products. Nanomedicines based on PLGA nanoparticles can offer tremendous opportunities in the diagnosis, monitoring, and treatment of various diseases.This Special Issue aims to focus on the bench-to-bedside development of PLGA nanoparticles including (but not limited to) design, development, physicochemical characterization, scale-up production, efficacy and safety assessment, and biodistribution studies of these nanomedicine formulations

Reusable Ultrasonic Tissue Mimicking Hydrogels Containing Nonionic Surface-Active Agents for Visualizing Thermal Lesions

The present study aims to identify a new recipe for reusable tissue mimicking phantoms that allows the optical visualization of thermal lesions produced in various applications of therapeutic ultrasound where thermal mechanisms are important. The phantom was made of polyacrylamide hydrogel containing a nonionic surface-active agent (NiSAA) as a temperature-sensitive indicator. Threshold temperature above which a thermal lesion is regarded to be formed in the phantom is controlled by selecting an NiSAA. In the present study, three NiSAAs of polyoxyethylene alkyl ether series with nominal clouding points of 66 degrees C, 70 degrees C, and 80 degrees C were chosen. Test phantoms were prepared with polyacrylamide hydrogel, corn syrup and NiSAAs [5% (w/v)]. Key acoustic properties of the three NiSAA hydrogels were found to be similar to those of human liver. The phantoms were optically transparent at room temperature (25 degrees C) and became opaque after exceeding the clouding points. The transparency was recovered on cooling, although the system demonstrated hysteresis. The phantoms were tested both in their ability to provide visualization of thermal lesions produced by high-intensity focused ultrasound and also to examine any characteristic differences in the shape of the lesions formed at different threshold temperatures. The present study suggests that the NiSAA polyacrylamide hydrogel will be of a practical use in quality assurance in various applications of therapeutic ultrasound where thermal mechanisms are important.KANG GS, 2009, SPRING C AC SOC KORLEE FT, 2009, THESIS JEJU NAT U JEKim YS, 2008, KOREAN J RADIOL, V9, P291, DOI 10.3348/kjr.2008.9.4.291GUNTUR SRR, 2008, P KJMP S SEP JEJ KOR, P70AARON B, 2007, J UROLOGY, V178, P1080CHOI MJ, 2007, P 7 INT S THER ULTR, P41Kumar S, 2006, COLLOID POLYM SCI, V284, P1459, DOI 10.1007/s00396-006-1506-7Khokhlova VA, 2006, J ACOUST SOC AM, V119, P1834, DOI 10.1121/1.2161440CHOI MJ, 2006, 6 INT S THER ULTR ISLafon C, 2005, ULTRASOUND MED BIOL, V31, P1383, DOI 10.1016/j.ultrasmedbio.2005.06.004Kuroda M, 2005, INT J ONCOL, V27, P175YING L, 2005, J ACOUST SOC KOREA, V24, P132Kennedy JE, 2004, ULTRASONICS, V42, P931, DOI 10.1016/j.ultras.2004.01.089DONALD MM, 2004, PHYS MED BIOL, V49, P2767MIYAKAWA M, 2002, P 2002 IEEE EMC INT, V2, P671Wu F, 2001, ULTRASOUND MED BIOL, V27, P1099Lu ZF, 1999, ULTRASOUND MED BIOL, V25, P1047Madsen EL, 1999, J ULTRAS MED, V18, P615GEORGE C, 1999, PHARM RES, V16, P562MIYAKAWA M, 1996, P 1996 IEEE MTT S IN, V2, P1089MADERSBACHER S, 1993, EUR UROL, V23, P39KUO IY, 1990, J ACOUST SOC AM, V88, P1679PARKER KJ, 1988, ULTRASOUND MED BIOL, V14, P127WILSON LS, 1984, ULTRASONIC IMAGING, V6, P278TAKAHASHI S, 1983, ILLUSTRATED COMPUTER, P18OPHIR J, 1982, ULTRASONIC IMAGING, V4, P163DONNELL MO, 1981, J APPL PHYS, V52, P1056GRITZALAS K, DERMATOL J

Odyssée au fil des interfaces: de la physico-chimie des macromolécules à l'enveloppe bactérienne, plate-forme interactive du micro-organisme avec son micro-environnement

This find is registered at Portable Antiquities of the Netherlands with number PAN-0001909

Microgravity Science and Applications: Program Tasks and Bibliography for Fiscal Year 1996

NASA's Microgravity Science and Applications Division (MSAD) sponsors a program that expands the use of space as a laboratory for the study of important physical, chemical, and biochemical processes. The primary objective of the program is to broaden the value and capabilities of human presence in space by exploiting the unique characteristics of the space environment for research. However, since flight opportunities are rare and flight research development is expensive, a vigorous ground-based research program, from which only the best experiments evolve, is critical to the continuing strength of the program. The microgravity environment affords unique characteristics that allow the investigation of phenomena and processes that are difficult or impossible to study an Earth. The ability to control gravitational effects such as buoyancy driven convection, sedimentation, and hydrostatic pressures make it possible to isolate phenomena and make measurements that have significantly greater accuracy than can be achieved in normal gravity. Space flight gives scientists the opportunity to study the fundamental states of physical matter-solids, liquids and gasses-and the forces that affect those states. Because the orbital environment allows the treatment of gravity as a variable, research in microgravity leads to a greater fundamental understanding of the influence of gravity on the world around us. With appropriate emphasis, the results of space experiments lead to both knowledge and technological advances that have direct applications on Earth. Microgravity research also provides the practical knowledge essential to the development of future space systems. The Office of Life and Microgravity Sciences and Applications (OLMSA) is responsible for planning and executing research stimulated by the Agency's broad scientific goals. OLMSA's Microgravity Science and Applications Division (MSAD) is responsible for guiding and focusing a comprehensive program, and currently manages its research and development tasks through five major scientific areas: biotechnology, combustion science, fluid physics, fundamental physics, and materials science. FY 1996 was an important year for MSAD. NASA continued to build a solid research community for the coming space station era. During FY 1996, the NASA Microgravity Research Program continued investigations selected from the 1994 combustion science, fluid physics, and materials science NRAS. MSAD also released a NASA Research Announcement in microgravity biotechnology, with more than 130 proposals received in response. Selection of research for funding is expected in early 1997. The principal investigators chosen from these NRAs will form the core of the MSAD research program at the beginning of the space station era. The third United States Microgravity Payload (USMP-3) and the Life and Microgravity Spacelab (LMS) missions yielded a wealth of microgravity data in FY 1996. The USMP-3 mission included a fluids facility and three solidification furnaces, each designed to examine a different type of crystal growth