Using a cultural-ecological framework to explore dietary beliefs and practices during pregnancy and lactation among women in Adivasi communities in the Nilgiris Biosphere Reserve, India.

This article explores maternal dietary beliefs and practices gathered through interviews with mothers of infants and young children in Adivasi communities in the Nilgiris Biosphere Reserve, India. Guided by focused ethnographic study methods, interviews were conducted with 33 key informants. We used a cultural-ecological framework to analyze and interpret the texts that were elicited from women about dietary beliefs and eating patterns during pregnancy and lactation. We identify differences between what women were advised to eat, felt they should eat, and reported consuming. The findings offer guidance for interventions to improve maternal diets in this vulnerable population.

Effect of processing parameters on the properties of peptide-containing PLGA microspheres.

The physico-chemical properties of biodegradable polylactide-co-glycolide (PLGA) microspheres containing the peptide salmon calcitonin (sCT) were affected by the processing parameters. The microsphere size increased with an increase in the viscosity of the polymer solution. Concentration of methanol and peptide in the dispersed phase had the most discernible effects with the combination causing external and internal porosity. Increasing sCT in the presence of methanol increased the surface area and porosity. The surface area also increased as the molecular weight of the polymer was decreased. At higher ratios of the dispersed phase volume to the continuous phase volume, the surface area and surface porosity were higher and the particle size was lower. Thus, the physico-chemical properties of the microspheres can be easily altered by varying the processing parameters allowing formation of microspheres with a range of properties. The microspheres may be used to evaluate the relationship between the properties and ultimate in-vivo performance.

Adsorption of salmon calcitonin to PLGA microspheres.

PURPOSE: The interaction of salmon calcitonin (sCT) and poly (d,l-lactide-co-glycolide) was detected during preparation and evaluation of microspheres. The purpose of this study was to quantitate the extent and nature of the interaction. METHODS: Blank microspheres were prepared by an aqueous emulsification solvent extraction technique. Adsorption studies were carried out at six concentrations of sCT and three concentrations of microspheres. Adsorption isotherms were constructed using the Langmuir and Freundlich treatments. RESULTS: Adsorption at 1 mg/ml sCT concentration resulted in almost complete depletion of the peptide from the adsorption medium with the time to reach maximum adsorption decreasing with increasing microsphere concentration. At sCT concentrations below 100 micrograms/ml, a true equilibrium occurred in 1 hour or less while at higher concentrations (up to 350 micrograms/ml), a transient equilibrium was reached in 1 to 2 hours, followed by further adsorption of the peptide. The adsorption followed the Langmuir isotherm at concentrations below 200 micrograms/ml, indicating formation of a monolayer. Multilayer interaction, described by the Freundlich isotherm, occurred at higher concentrations and resulted in complete depletion of sCT from the adsorption medium. The affinity constant during monolayer formation was 0.09 and the plateau surface concentration was 5.1 micrograms/mg. The multilayer peptide-peptide adsorption showed a lower affinity (0.025) but higher capacity (24 micrograms/mg) than the monolayer peptide-polymer adsorption. CONCLUSIONS: The results show that poly (d,l-lactide-co-glycolide) microspheres have a high adsorption capacity for sCT which must be considered in formulating a controlled delivery product of this peptide.

Solid tumour chemotherapy using implantable collagen-poly (HEMA) hydrogel containing 5-fluorouracil.

Implantable collagen-poly(HEMA) hydrogels containing the anticancer drug 5-fluorouracil (5-FU) have been prepared and evaluated for their efficacy towards a solid tumour fibrosarcoma in Wistar rats. The tumour was developed by inoculation of a 10% tumour-cell suspension in the anterior aspect of the hind limb. Four groups were studied--untreated control, intratumoural injection of free 5-FU, subcutaneous implantation of placebo and implantation of 5-FU-bearing hydrogel pellets (10 mm diameter x 1 mm thick) containing the drug in close proximity to the tumour. The hydrogel showed an improved antitumour activity over free 5-FU as evidenced by the gross tumour weight assessments and by [3H]thymidine incorporation in-vitro. This was attributed to the controlled and slow release of 5-FU compared with free 5-FU over the same period of treatment. The implantation of hydrogel could thus be a potential alternative to free 5-FU therapy in the treatment of solid tumours such as fibrosarcoma.

In vivo biocompatibility of collagen-poly(hydroxyethyl methacrylate) hydrogels.

Collagen-p(HEMA) hydrogels were subcutaneously implanted in rats for up to 6 month and the immediate short- and long-term tissue response to these implants was studied. Histopathological data indicated that the tissue reaction at the implant site progressed from an initial acute inflammatory response characterized by the presence of eosinophils and polymorphs to a chronic response marked by few macrophages, foreign body giant cells and fibroblasts. After one month a very thin fibrous capsule (approximately 11 microns thick) was observed around the implant. Even 6 month post-implantation, the capsule thickness was maintained at about 11-12 microns. No necrosis, calcification, tumorigenesis or infection was observed at the implant site up to 6 month. Fibrous capsule analysis showed that the collagen content and the capsule thickness were well within the threshold limits. The collagen-p(HEMA) hydrogels were found to be well-tolerated, non-toxic and highly biocompatible.