In Situ Impregnation of Silver Nanoclusters in Microporous Chitosan-PEG Membranes as an Antibacterial and Drug Delivery Percutaneous Device.

An in situ synthesis method for preparing silver nanoclusters (AgNCs) embedded in chitosan-polyethylene glycol (CS-PEG) membranes is disclosed. The aim is to develop implantable multifunctional devices for biofilm inhibition and drug release to reduce percutaneous device related complications (PDRCs). A multiple array of characterization techniques confirmed the formation of fluorescent AgNCs with sizes of ∼3 nm uniformly distributed in CS-PEG matrix and their active role in determining the fraction and interconnectivity of the microporous membranes. The presence and increasing contents of AgNCs enhanced the mechanical stability of membranes and decreased their susceptibility to degradation in the presence of lysozyme and H2O2. Moreover, the presence and increasing concentrations of AgNCs hindered biofilm formation against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) and enabled a sustainable release of an anti-inflammatory drug naproxen in vitro until 24 h. The overall results gathered and reported in this work make the AgNCs impregnated CS-PEG membranes highly promising multifunctional devices combining efficient antibacterial activity and biocompatibility with active local drug delivery.

In situ formation, structural, mechanical and in vitro analysis of ZrO2/ZnFe2O4 composite with assorted composition ratios.

The investigation underline the in situ formation of ZrO2/ZnFe2O4 composites and the resultant structural, morphological, mechanical and magnetic properties. The characterization results ensured the crystallization of tetragonal ZrO2 (t-ZrO2) and ZnFe2O4 phases at 900 °C. Depending on Zn2+/Fe3+ content, the composite system revealed a gradual increment in the phase yield of ZnFe2O4. The significance of monoclinic ZrO2 (m-ZrO2) is also evident in all the systems at 900 °C; however, the incremental heat treatment to 1300 °C indicated its corresponding loss, thus indicating the reverse m- â†’ t-ZrO2 transition. The crystallization of ZnFe2O4 as a secondary phase in the t-ZrO2 matrix is also affirmed from the morphological analysis. Mechanical studies accomplished good uniformity in all the investigated compositions despite the variation in the phase content of ZnFe2O4 in composite system. All the t-ZrO2/ZnFe2O4 composites ensured strong ferrimagnetic features and moreover better biocompatibility and non-toxicity characteristics were displayed from in vitro tests.

Composites based on zirconia and transition metal oxides for osteosarcoma treatment. Design, structural, magnetic and mechanical evaluation.

The formation of structurally stable composites of cubic zirconia (c-ZrO2) with selective transition metal oxides (α-Fe2O3, Mn3O4, NiO, Co3O4) is investigated. The results affirm the prospect to retain unique c-ZrO2 and transition metal oxide (TMO) structures in the composite form until 1400 °C. It is also shown that 30 mol% Y2O3 possess the ability to retain stable c-ZrO2 despite the existence of assorted TMO content in the composites. The elemental states of Fe3+, Mn2+/4+, Ni2+ and Co2+/3+ are confirmed from the corresponding α-Fe2O3, Mn3O4, NiO, and Co3O4. The magnetic properties are highly influenced by the quantity of TMO component while the c-ZrO2 plays a decisive role in the resultant mechanical properties. The wide range of properties delivered by the composites extends the possibility to probe for osteosarcoma treatment that demands optimal mechanical and magnetic features.