Natural and synthetic polymers for wounds and burns dressing

Highly open porous biodegradable poly(L-lactic acid) ¿PLLA scaffolds for tissue regeneration were fabricated by using ammonium bicarbonate as an efficient gas foaming agent as well as a particulate porogen salt. A binary mixture of PLLA-solvent gel containing dispersed ammonium bicarbonate salt particles, which became a paste state, was cast in a mold and subsequently immersed in a hot water solution to permit the evolution of ammonia and carbon dioxide within the solidifying polymer matrix. This resulted in the expansion of pores within the polymer matrix to a great extent, leading to well interconnected macroporous scaffolds having mean pore diameters of around 300-400 microm, ideal for high-density cell seeding. Rat hepatocytes seeded into the scaffolds exhibited about 95% seeding efficiency and up to 40% viability at 1 day after the seeding. The novelty of this new method is that the PLLA paste containing ammonium bicarbonate salt particles can be easily handled and molded into any shape, allowing for fabricating a wide range of temporal tissue scaffolds requiring a specific shape and geometry.

A Novel Fabrication Method of Macroporous Biodegradable Polymer Scaffolds Using Gas Foaming Salt as Porogen Additive

Regenerating bone with bioactive glass scaffolds: A review of in vivo studies in bone defect models.

The field of regenerative medicine has tremendous potential for improved treatment outcomes and has been stimulated by advances made in bioengineering over the last few decades. The strategies of engineering tissues and assembling functional constructs that are capable of restoring, retaining, and revitalizing lost tissues and organs have impacted the whole spectrum of medicine and health care. Techniques to combine biomimetic materials, cells, and bioactive molecules play a decisive role in promoting the regeneration of damaged tissues or as therapeutic systems. Hydrogels have been used as one of the most common tissue engineering scaffolds over the past two decades due to their ability to maintain a distinct 3D structure, to provide mechanical support for the cells in the engineered tissues, and to simulate the native extracellular matrix. The high water content of hydrogels can provide an ideal environment for cell survival, and structure which mimics the native tissues. Hydrogel systems have been serving as a supportive matrix for cell immobilization and growth factor delivery. This review outlines a brief description of the properties, structure, synthesis and fabrication methods, applications, and future perspectives of smart hydrogels in tissue engineering.

Smart Hydrogels in Tissue Engineering and Regenerative Medicine.

Significant progress has been made over the past 25 years in the development of in vitro-engineered substitutes that mimic human skin, either to be used as grafts for the replacement of lost skin, or for the establishment of in vitro human skin models. In this sense, laboratory-grown skin substitutes containing dermal and epidermal components offer a promising approach to skin engineering. In particular, a human plasma-based bilayered skin generated by our group, has been applied successfully to treat burns as well as traumatic and surgical wounds in a large number of patients in Spain. There are some aspects requiring improvements in the production process of this skin; for example, the relatively long time (three weeks) needed to produce the surface required to cover an extensive burn or a large wound, and the necessity to automatize and standardize a process currently performed manually. 3D bioprinting has emerged as a flexible tool in regenerative medicine and it provides a platform to address these challenges. In the present study, we have used this technique to print a human bilayered skin using bioinks containing human plasma as well as primary human fibroblasts and keratinocytes that were obtained from skin biopsies. We were able to generate 100 cm2, a standard P100 tissue culture plate, of printed skin in less than 35 min (including the 30 min required for fibrin gelation). We have analysed the structure and function of the printed skin using histological and immunohistochemical methods, both in 3D in vitro cultures and after long-term transplantation to immunodeficient mice. In both cases, the generated skin was very similar to human skin and, furthermore, it was indistinguishable from bilayered dermo-epidermal equivalents, handmade in our laboratories. These results demonstrate that 3D bioprinting is a suitable technology to generate bioengineered skin for therapeutical and industrial applications in an automatized manner.

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3D bioprinting of functional human skin: production and in vivo analysis

Steam distilled oil of the fresh leaves of lemon grass, Cymbopogon citratus (DC) Stapf. of Delhi region was analyzed by GLC and GC-MS. Twenty two compounds constituting about 99.7% of the volatile oil were characterized. The oil was found to contain high amount of monoterpe-nes (95.9%) constituting mainly geranial (52.3%), cis-pinocarveol (20.2%), neral (9.8%) and limonene-1, 2-epoxide (3.6%).

Volatile Constituents of Cymbopogon citratus (DC.) Stapf. Leaves

Clinical trials, also known as clinical studies, are designed to help us find out how to give a new treatment safely and effectively to people. A clinical trial is an organized research study designed to investigate new methods of preventing, detecting, diagnosing, or treating an illness or disease and attempt to improve a patient’s quality of life. The concept of outsourcing for the development and global studies on new drugs has become widely accepted in the pharmaceutical industry due to its cost and uncertainty. India is going to be the most preferred location for contract pharma research and development due to its high patient enrolment rate, human resources, and technical skills, adoption/amendment/implementation of rules/laws by regulatory authorities, reliable data quality and changing economic environment. But still ‘miles to go’ to fulfill the pre-requisites to ensure India’s success. In spite of all the pitfalls like government policies and weak patent law, lack of ICH-GCP compliant sites, lack of awareness and education amongst patients and bureaucratic hurdle, the country is ambitious and optimist to attract multinational pharmaceutical companies to conduct their clinical trials in India.

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Onkar Singh

Papers

Volatile Constituents of Cymbopogon citratus (DC.) Stapf. Leaves

OPPORTUNITIES AND GROWTH OF CONDUCT CLINICAL TRIALS IN INDIA Review Article

New Anthraquinones from Rubia cordifolia Roots