Agnieszka Adamus

Facile and durable antimicrobial finishing of cotton textiles using a silver salt and UV light

In this study, we present facile antimicrobial finishing of cotton textiles. Screen printing was used for surface-finishing of cotton using a printing paste containing silver nitrate. UVC irradiation was applied to convert silver nitrate into a color product, thus also changing the color of the textiles. The color, its strength and stability of samples, depend on absorbed UVC energy and the formula of the printing paste. Scanning electron microscopy with the energy dispersive X-ray spectrometry revealed formation of silver particles on cotton threads; X-ray diffraction analysis and the time-of-flight secondary ion mass spectrometry did not provide clear information on these products. Microbiological studies revealed that the samples inhibited proliferation of Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Washing fastness tests confirmed resistance of the samples to at least 50 washings. Additionally, the inhibition zones increased as the number of washing cycles increased, which is unique for such samples. This work also presents an approach to the design of antimicrobially finished workwear.

Biocompatibility of Modified Bionanocellulose and Porous Poly(ϵ-caprolactone) Biomaterials

Biocompatibility of modified bionanocellulose (BC) and porous poly(ϵ caprolactone) (PCL) were compared to UHMWPE. For all the materials lack of cytotoxic effect to mouse fibroblasts was observed in vitro. In vivo study, subcutaneous implantations in Wistar rats, lasted for seven, 14, and 30 days. Subsequently the composition of surrounding tissue and explants surface changes was evaluated. No symptoms of acute inflammation were observed. Surrounding tissue thickness, the number of granulocytes, lymphocytes, macrophages, and blood vessels differed in time and revealed regular healing process. It is concluded that investigated PCL and BC are the materials with superior biocompatibility with high application potential.

The influence of selected NSAIDs on volume phase transition in poly(2-(2-methoxyethoxy)ethyl methacrylate) hydrogels

Hydrogels exhibiting Volume Phase Transition (VPT) are considered as useful biomaterials for the preparation of various drug delivery systems. Such hydrogels are commonly based on thermo-responsive polymers, such as poly(2-(2-methoxyethoxy)ethyl methacrylate) (PMEO2MA), that have lower critical solution temperature (LCST) in aqueous solutions. In this work, PMEO2MA hydrogels were used as model systems to study the influence of encapsulated drugs, such as ibuprofen and salicylate sodium salts, on the temperature and dynamics of the VPT. Both thermo-optical analysis and differential scanning calorimetry have shown that the VPT becomes broader and shifts towards higher temperatures with increasing drug concentration. Three regimes of VPT in PMEO2MA gels were distinguished. The first two, related to the breaking of the strong water-polymer interactions and to the network collapse, slow down with increasing drug concentration. The last regime, corresponding to the slow diffusion of a residual solution from a collapsing network, becomes visible only for systems with high content of drug. Raman spectroscopy studies show that the observed effect is not connected to direct interactions between polymers and drugs. This suggests that the drug molecules are able to stabilise water-polymer interactions in thermo-responsive hydrogels. Consequently, they are able to modulate VPT and have a significant influence on the delivery process.

In vivo evaluation of nerve guidance channels of PTMC/PLLA porous biomaterial.

Introduction Peripheral nerve disruptions, frequently occurring during limb injuries, give rise to serious complications of patients recovery resulting from limitations in neural tissue regeneration capabilities. To overcome this problem bridging techniques utilizing guidance channels gain their importance. Biodegradable polymeric tubes seem to be more prospective then non-degradable materials – no necessity of implant removal and possibilities of release of incorporated drugs or biologically active agents that may support nerve regeneration process are the main advantages. Material and methods Polymer blend of commercial poly(L-lactic acid) (PLLA) and in-house synthesized poly(trimethylene carbonate) (PTMC) were processed in an organic solvent – phase inversion process on a supporting rod – to form a guidance porous tube of 1.1 mm inner diameter. In vivo experiments on rats cut femoral nerve by using either the tubes or end-to-end suturing (control group) involved 22 and 19 rats, respectively. Motor recovery of operated limbs, neuroma occurrence and histopathology of explanted nerves were evaluated after 30, 60 and 90 days of implantation. Results Motor recovery of the limbs was of similar rate for the two animal groups. The neuroma formation was evident in over 90% control specimens, while for the bridging group it was less than 40% of all evaluable samples (p = 0.0022). Biocompatibility of applied materials was affirmed by moderate tissue response. Conclusions Application of the biodegradable PLLA/PTMC polymeric tubes effectively supports regeneration of discontinued nerves. The applied material prevents neuroma formation, by reducing the scar tissue formation time and, thus, accelerating the process of neural tissue restoration.

Specific Heat Capacity of Sołtmany and NWA 4560 Meteorites

Veins of clay and carbonate in the nakhlite meteorite Lafayette formed by dissolution and replacement of olivine.NanoSIMS measurements record δD values up to +4725‰ in Lafayette which reveal martian waters of crustal origin are incorporated into the smectite and adjacent olivine.