The effect of artisanal preservation methods on nutritional security of “Mukene” Rastrineobola argentea caught from Lakes Victoria and Kyoga in Uganda

The artisanal fish preservation methods in Uganda are characterized by extreme operating conditions. Consequently, vital nutritional components diminish in value and quantity which renders fish consumer nutritionally insecure. To establish the magnitude of nutritional loss, duplicate samples of Mukene Rastrineobola argentea were collected from Kiyindi landing site on L. Victoria and Moone landing site on L. Kyoga. Each set of duplicate samples was divided into five portions and kept on ice. For each preservation method a portion was processed into respective products at Food Bioscience and Agri-Business Laboratories aside from the control (fresh) sample. Both preserved and control samples were analysed for nutrient loss at Department of Chemistry, Makerere University using AOAC methods. The composition of fatty acids was determined by methanolysis gas chromatography and Mass spectrophotometry of the resultant methyl esters. The results indicate that nutrients of all preserved samples did not vary significantly from the control except for some fatty acids. The Eicosapentaenoic acid (EPA) in fresh samples declined from 6.72% to 1.08% in deep-fried samples constituting 83.93% nutrient loss. The sum ratio w3:w6 as well as EPA: DHA (Docosahexaenoic) ratio in fried samples also varied significantly (p<0.5) lower than 0.668 and 0.20 for the average of either preservation methods and experts recommended ratio respectively. Further research has been recommended to ascertain the causative factor, since Mukene frying is being promoted in the Great lakes region as alternative method to sun-drying. In conclusion, regular consumers of fried Mukene do not benefit much from the nutritional and health attributes of Omega 3 and 6.

A Global Crisis for Seagrass Ecosystems

Seagrasses, marine flowering plants, have a long evolutionary history but are now challenged with rapid environmental changes as a result of coastal human population pressures. Seagrasses provide key ecological services, including organic carbon production and export, nutrient cycling, sediment stabilization, enhanced biodiversity, and trophic transfers to adjacent habitats in tropical and temperate regions. They also serve as “coastal canaries,” global biological sentinels of increasing anthropogenic influences in coastal ecosystems, with large-scale losses reported worldwide. Multiple stressors, including sediment and nutrient runoff, physical disturbance, invasive species, disease, commercial fishing practices, aquaculture, overgrazing, algal blooms, and global warming, cause seagrass declines at scales of square meters to hundreds of square kilometers. Reported seagrass losses have led to increased awareness of the need for seagrass protection, monitoring, management, and restoration. However, seagrass science, which has rapidly grown, is disconnected from public awareness of seagrasses, which has lagged behind awareness of other coastal ecosystems. There is a critical need for a targeted global conservation effort that includes a reduction of watershed nutrient and sediment inputs to seagrass habitats and a targeted educational program informing regulators and the public of the value of seagrass meadows.

Grafting BSA onto poly[(L-lactide)-co-carbonate] microspheres by click chemistry

Model protein bovine serum albumin (BSA) was covalently grafted onto poly[(L-lactide)co-carbonate] microsphere surfaces by "click chemistry." The grafting was confirmed by confocal laser scanning microscopy and X-ray photoelectron spectroscopy. The maximum amount of surface-grafted BSA was 45 mg.g(-1). The secondary structure of the grafted BSA was analyzed by FTIR and the results demonstrated that the grafting did not affect protein structure. This strategy can also be used on microspheres prepared from poly(L-lactide)/poly[(L-lactide)-co-carbonate] blend materials.

The Surface Modification of Hydroxyapatite Nanoparticles by the Ring Opening Polymerization of gamma-Benzyl-L-glutamate N-carboxyanhydride

The surface modification of hydroxyapatite (HA) nanoparticles by the ring opening polymerization (ROP) of gamma-benzyl-L-glutamate N-carboxyanhydride (BLG-NCA) was proposed to prepare the poly(gamma-benzyl-L-glutamate) (PBLG)-grafted HA nanoparticles (PBLG-g-HA) for the first time. HA nanoparticles were firstly treated by 3-aminopropylthriethoxysilane (APS) and then the terminal amino groups of the modified HA particles initiated the ROP of BLG-NCA to obtain PBLG-g-HA. The process was monitored by XPS and FT-IR. The surface grafting amounts of PBLG on HA ranging from 12.1 to 43.1% were characterized by thermal gravimetric analysis (TGA). The powder X-ray diffraction (XRD) analysis confirmed that the ROP only underwent on the surface of HA nanoparticles without changing its bulk properties. The SEM measurement showed that the PBLG-g-HA hybrid could form an interpenetrating net structure in the self-assembly process.

Core Crosslinking of Biodegradable Block Copolymer Micelles Based on Poly(ester carbonate)

A biodegradable amphiphilic block copolymer, PEG-b-P(LA-co-MAC), was used to prepare spherical micelles consisting of a hydrophobic P(LA-co-MAC) core and a hydrophilic PEG shell. To improve their stability, the micelles were crosslinked by radical polymerization of the double bonds in the hydrophobic blocks. The crosslinked micelles had similar sizes and a narrow size distribution compared to their uncrosslinked precursor. The improved stability of the crosslinked micelles was confirmed by measurements of the CMC and a thermodynamic investigation. These micelles can internalize into Hela cells in vitro as demonstrated by inverted fluorescence microscopy and CLSM. These stabilized nanoscale micelles have potential use in biomedical applications such as drug delivery and disease diagnosis.

Layer-by-Layer Buildup of Poly(L-glutamic acid)/Chitosan Film for Biologically Active Coating

A new biocompatible film based on chitosan and poly(L-glutamic acid) (CS/PGA), created by alternate deposition of CS and PGA, was investigated. FT-IR spectroscopy, UV-vis spectroscopy and QCM were used to analyze the build-up process. The growth of CS and PGA deposition are both exponential to the deposition steps at first. After about 9 (CS/PGA) depositions, the exponential to linear transition takes place. QCM measurements combined with UV-vis spectra revealed the increase in the multilayer film growth at different pH (4.4, 5.0 and 5.5). The build-up of the multilayer stops after a few depositions at pH = 6.5. A muscle myoblast cell (C2C12) assay showed that (CS/PGA)(n) multilayer films obviously promote C2C12 attachment and growth.

Folate-Conjugated Micelles and Their Folate-Receptor-Mediated Endocytosis

A folate-conjugated copolymer PEG-PLA-PLL/folate was synthesized and mixed with pure PEG-PLA-PLL and a fluorescent model drug mFITC to prepare folate-conjugated micelles. The distribution of micelles was studied on cancer-cell-bearing mice via frozen slicing. The results show that mFITC is successfully encapsulated into folate(+) and folate(-)micelles; PEG-PLA-PLL micelles the latter can be internalized by both HeLa and CHO cells without selectivity due to their cationic surface charges, while folate(+)micelles exhibit more preferential endocytosis by HeLa cells than by CHO cells. The folate(-)micelles showed retention in both organs and tumors. The folate(+)micelles are a promising active targeting drug delivery system for FR over-expressing cells and they accumulate in tumor beds.