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In this study, lauric acid-coated, superparamagnetic, nanoparticle-based magnetic fluids of different ferrites (Fe(3)O(4), MnFe(2)O(4), and CoFe(2)O(4)) were prepared and compared in terms of heating ability and biocompatibility to evaluate the feasibility of use in hyperthermia treatment of cancer. All the magnetic fluids prepared had particles of average sizes 9-11 nm. Heating ability of these magnetic fluids was evaluated by calorimetric measurement of specific absorption rate (SAR) at 300 kHz frequency and 15 kA/m field. Fe(3)O(4) and MnFe(2)O(4) showed higher SAR (120 and 97 W/g of ferrite, respectively) than CoFe(2)O(4) (37 W/g of ferrite). In vitro study on BHK 21 cell lines showed dose-dependent cell viability for all the magnetic fluids. Threshold-biocompatible ferrite concentration for all the magnetic fluids was 0.1 mg/mL. Above 0.2 mg/mL, CoFe(2)O(4) was more toxic than the other magnetic fluids. On intravenous injection of different doses (50, 200, and 400 mg/kg body weight) of magnetic fluids in mice, no significant changes in hematological and biochemical parameters were observed for Fe(3)O(4) and MnFe(2)O(4). With CoFe(2)O(4), an increase in SGPT levels at a dose rate of 400 mg/kg body weight was observed, indicating its mild hepatotoxic effect. However, histology of different vital organs showed no pathological changes for all the three magnetic fluids. Further, long term in vivo evaluation of biocompatibility of the lauric acid-coated ferrites is warranted. This study shows that lauric acid-coated, superparamagnetic Fe(3)O(4) and MnFe(2)O(4) may be used for hyperthermia treatment and are to be preferred over CoFe(2)O(4).

The interactions of nanomaterials with plasma proteins have a significant impact on their in vivo transport and fate in biological fluids. This article discusses the binding of human serum albumin (HSA) to poly(amidoamine) [PAMAM] dendrimers. We use protein-coated silica particles to measure the HSA binding constants (K b) of a homologous series of 19 PAMAM dendrimers in aqueous solutions at physiological pH (7.4) as a function of dendrimer generation, terminal group, and core chemistry. To gain insight into the mechanisms of HSA binding to PAMAM dendrimers, we combined 1H NMR, saturation transfer difference (STD) NMR, and NMR diffusion ordered spectroscopy (DOSY) of dendrimer−HSA complexes with atomistic molecular dynamics (MD) simulations of dendrimer conformation in aqueous solutions. The binding measurements show that the HSA binding constants (K b) of PAMAM dendrimers depend on dendrimer size and terminal group chemistry. The NMR 1H and DOSY experiments indicate that the interactions between HSA and PAMAM dendrimers are relatively weak. The 1H NMR STD experiments and MD simulations suggest that the inner shell protons of the dendrimers groups interact more strongly with HSA proteins. These interactions, which are consistently observed for different dendrimer generations (G0-NH2 vs G4-NH2) and terminal groups (G4-NH2 vs G4-OH with amidoethanol groups), suggest that PAMAM dendrimers adopt backfolded configurations as they form weak complexes with HSA proteins in aqueous solutions at physiological pH (7.4).

The core–shell polymeric nanofiber, owing to its better controlled release of embedded or encapsulated drugs in contrast with the single-compartment nanofibers, has been extensively studied for biomedical applications such as tissue engineering and wound healing. Electrospinning with co-axial needles is the dominant technique to fabricate nanofiber mat, however, associated with potential limitations such as high voltage requirement, costly equipment, slow deposition rate, required trained personal, not suitable in situ fabrication, and direct deposition of core–shell nanofibers on the wound at patient bedside. To address the above limitations, the work aims to introduce a novel co-axial airbrushing method to fabricate core–shell nanofibers using a simple setup and low-cost equipment, yet having a unique ability for fabrication at patient bedside and direct deposition on wound bed. Air-brush with a coaxial needle is designed to flow two different polymers solution with model biomolecules through core [PEO (polyethylene oxide)/poly-dl-lactide/PCL (polycaprolactone)] and shell (PCL/PEO) needle for the fabrication of the model core–shell nanofiber. Various processing parameters such as flow rate, air pressure, working distance, and concentration of polymer solution which affect the morphology of core–shell nanofibers were studied and found to have a prominent effect. The PCL–PEO nanofiber possesses a defined shell and core structure, tunable sustained release behavior of model proteins (bovine serum albumin and basic fibroblast growth factor; bFGF), and improved mechanical strength. In vitro interaction of human bone marrow-derived mesenchymal stem cells with core–shell fibers demonstrated the cytocompatibility and proliferative and differentiative (for bFGF loaded) properties of the core–shell nanofiber mat. Co-axial airbrushing can be used as a superior less-expensive technique for the fabrication of biomolecules/drug encapsulated core–shell fibers scaffold at patient bedside, which can mimic complex in vivo environment and could modulate cells behavior close to their in vivo condition for tissue regeneration and wound healing.