The present study was initiated to understand the effect of PLGA concentration, PVA concentration, internal-external phase ratio, homogenization speed, and homogenization time on mean particle size, zeta potential, and percentage drug encapsulation using fractional factorial design. Using PLGA (50-50) as the carrier, hyaluronidase loaded PLGA nanoparticles were prepared using double emulsion solvent evaporation technique. The particle size was analyzed by dynamic light scattering technique and protein content by Lowry method. The study showed that homogenization speed as an independent variable had maximum effect on particle size and zeta potential. Internal-external phase volume ratio had maximum effect on drug encapsulation. Mean particle size also had high dependency on the combined effect of PVA concentration and phase volume ratio. Using fractional factorial design particle size of <400 nm, zeta potential of <−30 mV, and percentage encapsulation of 15–18% were achieved.

Every year more than 12,000 people in US alone suffer from spinal cord injury. However, complete recovery of physical function is difficult due to multiple factors involved in disease progression. Currently available therapeutic regimens do not address all the factors concerned with the disease progression. The present review focuses mainly on the role of immune cells in progression of spinal cord injury and the drugs that target these immune cells. Literature search shows that inflammatory reactions and subsequent reactions that follow direct injury to spinal cord are sometimes responsible for the severity of the disease. Therefore, for design of proper treatment regimen a deep understanding in this area is required. Understanding the pathophysiology will help in creating delivery system that can target multiple factors involved in progression of spinal cord injury. A combination of various treatment strategies is required to reduce the disability in patients with spinal cord injury.

Extracts from natural products, especially microorganisms, have served as a valuable source of diverse molecules in many drug discovery efforts and led to the discovery of several important drugs. Identification of microbial strains having promising biological activities and purifying the bio-molecules responsible for the activities, have led to the discovery of many bioactive molecules. Extracellular, as well as intracellular, extracts of the metabolites of thirty-six bacterial and twenty-four fungal isolates, grown under unusual conditions such as high temperature, high salt and low sugar concentrations, were in vitro tested for their cytotoxic potential on various cancer cell lines. The extracts were screened on HeLa and MCF-7 cell lines to study the cytotoxic potential. Nuclear staining and flow cytometric studies were carried out to assess the potential of the extracts in arresting the cell cycle. The crude ethylacetate extract of isolate F-21 showed promising results by MTT assay with IC 50 as low as 20.37±0.36 μg/mL on HeLa, and 44.75±0.81 μg/mL on MCF-7 cells, comparable with Cisplatin. The isolate F-21 was identified as Aspergillus sp. Promising results were also obtained with B-2C and B-4E strains. Morphological studies, biochemical tests and preliminary chemical investigation of the extracts were also carried out.Uniterms: Anticancer. Cytotoxicity. Flow cytometry. Microbial extracts. MTT assay.Extratos de produtos naturais, especialmente de microrganismos, constituíram-se em fonte valiosa de diversas moléculas em muitas descobertas de fármacos e levaram à descoberta de fármacos importantes. A identificação de espécies microbianas que apresentam atividade biológica e a purificação de biomoléculas responsáveis pelas atividades levou à descoberta de muitas moléculas bioativas. Extratos extracelulares tanto quanto intracelulares de metabólitos de 36 isolados de bactérias e 24 isolados de fungos, que cresceram sob condições não usuais, como alta temperatura, alta concentração de sal e baixa concentração de açúcar, foram testados in vitro quanto ao seu potencial citotóxico em várias linhagens de câncer. Os extratos foram ensaiados em células HeLa e MCF-7 para o estudo do potencial citotóxico. A coloração nuclear e os estudos de citometria de fluxo foram realizados para avaliar o potencial dos extratos em bloquear o ciclo celular. O extrato bruto em acetato de etila do isolado F-21 mostrou resultados promissores no ensaio de MTT, com IC 50 de 20,37±0,36 μg/mL em células HeLa e 44,.75±0,81 μg/mL em células MCF-7, comparativamente à cisplatina. O isolado F-21 foi identificado como Aspergillus sp. Resultados promissores foram obtidos com cepas B-2C e B-4E. Realizaram-se, também, estudos morfológicos, testes bioquímicos e investigação química preliminar dos extratos.Unitermos: Anticâncer. Citotoxicidade. Citometria de fluxo. Extratos microbianos. Ensaios MTT.

The cultural conditions for acid protease production by Aspergillus niger was optimised using factorial design experiments and one factor-at-a time approach. In the production medium casein served as substrate and protease activity was measured in terms of tyrosine yield. The yield was further improved through UV mutation. Tyrosine yield amounted to 29.22 mg / g on casein substrate. Protease from this microbial strain was mesophilic. The enzyme was stable over a wide temperature range (30 to 45 °C) with maximum activity at 40 °C and showed better activity under acidic conditions. Also the extracted protease exhibited good tolerance towards organic solvents, surfactants and showed an increase in activity in presence of Ca2+. UV mutant showed 37.2 % increase in yield over the natural selectant and had better pH and thermostability. SDS PAGE showed 27.5 kDa as molecular size of the enzyme. This was further confirmed by zymography and gel filtration (Sephadex G-50). An improved enzyme yield and a better pH and thermal stability were achieved by using a combination of cultural condition optimization and mutation technique.

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