Wyniki wyszukiwania - BazTech

1

Protein release from different forms of polylactide and alginate composite carriers

Morawska-Chochół Anna

Engineering of Biomaterials

|

2023

|

vol. 26, no. 169

2--10

EN

The development of composite biomaterials constituting both a porous scaffold for filling tissue defects (especially bone tissue) and a carrier of biologically active substances (proteins) is an innovative approach of the presented research. The paper presents the following studies of obtained composites: model protein (bovine serum albumin, BSA) release, changes in microstructure during incubation and bioactive potential in a simulated biological environment (based on scanning electron microscopy with X-ray microanalysis – SEM/EDS – and infrared spectroscopy – FTIR). Three types of composites with a poly(L-lactide) matrix PLLA were investigated. PLA fibres covered with silica-calcium sol, calcium alginate fibres and calcium alginate beads were used as modifiers of the PLA matrix and carriers of protein. Process of releasing albumin proceeded differently depending on the material and form of the carrier. In the case of calcium alginate fibres, almost all protein was released within 14 days. For the remaining materials, this amount was reached after 3 weeks. All tested composites showed bioactive potential connected with apatite precipitation during incubation in a simulated biological environment. However, coating PLA fibres with silica-calcium sol significantly increased this effect. The highest cell viability was observed for a biomaterial modified by calcium alginate beads.

2

A one-step in vitro continuous flow assessment of protein release from core-shell polymer microcapsules designed for therapeutic protein delivery

Kupikowska-Stobba Barbara, Grzeczkowicz Marcin, Lewińska Dorota

Biocybernetics and Biomedical Engineering

|

2021

|

Vol. 41, no. 4

1347--1364

EN

Developing accurate methods for the assessment of therapeutic protein release from polymer drug delivery systems (microcapsules, microspheres, nanoparticles, 3D-printed systems) is of paramount importance for new formulation development. The most straightforward method for protein release assessment is spectrophotometric analysis of the release medium surrounding the formulation. However, direct spectrophotometric analysis is inapplicable to formulations releasing interfering compounds (coencapsulated drugs, additives) absorbing light in the same spectrum as proteins. Conventional protein release assays also require frequent release medium sampling and replacement, which reduces their accuracy. We propose a one-step method to assess protein release from core/shell microcapsules eliminating the need for sampling and allowing selective real-time protein quantitation in the release medium. To prevent spectral interferences, released protein is differentiated from interfering compounds by employing a colorimetric protein assay reagent, forming a colour complex selectively with the protein, as the release medium. To eliminate sampling, we employed a continuous flow closed loop set-up, where the release medium is constantly circulating between microcapsule-containing tank and spectrophotometer. A series of colorimetric protein assay reagents (bromocresol green, tetrabromophenol blue, eosin B, eosin Y, biuret) were evaluated in terms of their applicability as the release medium in described system. Only biuret reagent was found compatible with proposed method due to formation of color complex stable over extended period of time and low adsorption to microcapsules. Presented method allowed effective evaluation of albumin release from alginate-polyethersulfone microcapsules with accuracy equal to conventional ‘sample and separate’ technique. Albumin release followed first-order kinetics with plateau reached after 19 h.

3

Effect of sonication reactor geometry on cell disruption and protein release from yeast cells

Bałdyga J., Jasińska M., Dzięgielewska M., Żochowska M.

Chemical and Process Engineering

|

2018

|

Vol. 39, nr 4

475-–489

EN

The measured rate of release of intercellular protein from yeast cells by ultrasonication was applied for evaluating the effects of sonication reactor geometry on cell disruption rate and for validation of the simulation method. Disintegration of two strains of Saccharomyces cerevisiae has been investigated experimentally using a batch sonication reactor equipped with a horn type sonicator and an ultrasonic processor operating at the ultrasound frequency of 20 kHz. The results have shown that the rate of release of protein is directly proportional to the frequency of the emitter surface and the square of the amplitude of oscillations and strongly depends on the sonication reactor geometry. The model based on the Helmholtz equation has been used to predict spatial distribution of acoustic pressure in the sonication reactor. Effects of suspension volume, horn tip position, vessel diameter and amplitude of ultrasound waves on the spatial distribution of pressure amplitude have been simulated. A strong correlation between the rate of protein release and the magnitude of acoustic pressure and its spatial distribution has been observed. This shows that modeling of acoustic pressure is useful for optimization of sonication reactor geometry.