Magnetic nanoparticles that are currently explored for various biomedical applications exhibit a high propensity to minimize total surface energy through aggregation. This study introduces a unique, thermoresponsive nanocomposite design demonstrating substantial colloidal stability of superparamagnetic Fe3O4 nanoparticles (SPIONs) due to a surface-immobilized lipid layer. Lipid coating was accomplished in different buffer systems, pH 7.4, using an equimolar mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and L-α-dipalmitoyl-phosphatidyl glycerol (DPPG). Particle size and zeta potential were measured by dynamic laser light scattering. Heating behavior within an alternating magnetic field was compared between the commercial MFG-1000 magnetic field generator at 7 mT (1 MHz) and an experimental, laboratory-made magnetic hyperthermia system at 16.6 mT (13.7 MHz). The results revealed that product quality of lipid-coated SPIONs was significantly dependent on the colloidal stability of uncoated SPIONs during the coating process. Greatest stability was achieved at 0.02 mg/mL in citrate buffer (mean diameter = 80.0 ± 1.7 nm; zeta potential = −47.1 ± 2.6 mV). Surface immobilization of an equimolar DPPC/DPPG layer effectively reduced the impact of buffer components on particle aggregation. Most stable suspensions of lipid-coated nanoparticles were obtained at 0.02 mg/mL in citrate buffer (mean diameter = 179.3 ± 13.9 nm; zeta potential = −19.1 ± 2.3 mV). The configuration of the magnetic field generator significantly affected the heating properties of fabricated SPIONs. Heating rates of uncoated nanoparticles were substantially dependent on buffer composition but less influenced by particle concentration. In contrast, thermal behavior of lipid-coated nanoparticles within an alternating magnetic field was less influenced by suspension vehicle but dramatically more sensitive to particle concentration. These results underline the advantages of lipid-coated SPIONs on colloidal stability without compromising magnetically induced hyperthermia properties. Since phospholipids are biocompatible, these unique lipid-coated Fe3O4 nanoparticles offer exciting opportunities as thermoresponsive drug delivery carriers for targeted, stimulus-induced therapeutic interventions.

Dual functional hierarchically assembled nanostructures, with two unique functions of carrying therapeutic cargo electrostatically and maintaining radiolabeled imaging agents covalently within separate component building blocks, have been developed via the supramolecular assembly of several spherical cationic shell cross-linked nanoparticles clustered around a central anionic shell cross-linked cylinder. The shells of the cationic nanoparticles and the hydrophobic core domain of the anionic central cylindrical nanostructure of the assemblies were utilized to complex negatively charged nucleic acids (siRNA) and to undergo radiolabeling, respectively, for potential theranostic applications. The assemblies exhibited exceptional cell transfection and radiolabeling efficiencies, providing an overall advantage over the individual components, which could each facilitate only one or the other of the functions.

A rapid and efficient approach for the preparation and modification of a versatile class of functional polymer nanoparticles has been developed, for which the entire engineering process from small molecules to polymers to nanoparticles bypasses typical slow and inefficient procedures and rather employs a series of steps that capture fully the “click” chemistry concepts that have greatly facilitated the preparation of complex polymer materials over the past decade. The construction of various nanoparticles with functional complexity from a versatile platform is a challenging aim to provide materials for fundamental studies and also optimization toward a diverse range of applications. In this paper, we demonstrate the rapid and facile preparation of a family of nanoparticles with different surface charges and functionalities based on a biodegradable polyphosphoester block copolymer system. From a retrosynthetic point of view, the nonionic, anionic, cationic, and zwitterionic micelles with hydrodynamic diameters between 13 and 21 nm and great size uniformity were quickly formed by suspending, independently, four amphiphilic diblock polyphosphoesters into water, which were functionalized from the same parental hydrophobic-functional AB diblock polyphosphoester by click-type thiol-yne reactions. The well-defined (PDI 1.2) hydrophobic-functional AB diblock polyphosphoester was synthesized by an ultrafast (5 min) organocatalyzed ring-opening polymerization in a two-step, one-pot manner with the quantitative conversions of two kinds of cyclic phospholane monomers. The whole programmable process starting from small molecules to nanoparticles could be completed within 6 h, as the most rapid approach for the anionic and nonionic nanoparticles, although the cationic and zwitterionic nanoparticles required ca. 2 days due to purification by dialysis. The micelles showed high biocompatibility, with even the cationic micelles exhibiting a 6-fold lower cytotoxicity toward RAW 264.7 mouse macrophage cells, as compared to the commercial transfection agent Lipofectamine.

Poor solubililty of drugs is the major obstacle associated with formulation development. Application of nanotechnology in the formulation development of poorly soluble drugs as nanosuspensions offers the opportunity to address many of the deficiencies associated with these compounds. Therefore, the aim of present study was to develop and evaluate nanosuspensions of albendazole in order to enhance its dissolution, which in turn will ehnace its oral bioavailability. Different nanosuspensions of albendazole were prepared using high pressure homogenization and ultrasonic homogenization techniques. The preliminary study showed that smaller particle sizes of drug were obtained by increasing stirring rate, stirring time, ultrasound intensity and number of cycles. Three different stabilizers (poloxamer 188, polyvinyl alcohol [PVA] and polyvinyl pyrrolidone [PVP]) were investigated either alone or in combination to produce nanoususpensions. Prepared nanoparticles were characterized physically using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction. Prepared formulations were also subjected to in vitro dissolution studies in 0.1 N HCl. The results revealed that poloxamer 188 produces nanoparticles with significantly larger particle size than PVA and PVP. However, combination of PVA and PVP produces nanoparticles with significantly smaller size than other formulations. DSC and X-ray diffraction showed that the crystallinity of the drug was decreased. The dissolution rate of the drug in 0.1 N HCl was significantly higher due to the reduction of the particle size of different formulations and the presence of the hydrophilic stabilizers.

A novel potentiometric sensor was prepared, characterized and utilized for static and continuous determination of cefazolin sodium (CFZN). Several metal-ion complexes and anion exchangers were tested as electroactive materials in plasticized polymeric membranes for selective detection of CFZN. Among different electroactive species tridodecyl methyl ammonium chloride (TDMAC) doped membrane electrode was found to exhibit optimal response characteristics. The optimized membrane sensor exhibited near-Nernstian responses (-55.64 mV decade-1) over CFZN concentration range of 0.41–10 mM as measured in 50 mM acetate buffer, pH 5.5. The proposed sensor offers the advantage selectivity, does not require pre-treatment and possible interfacing with computerized and automated systems. It is worth noting that the developed membrane electrode exhibited good selectivity toward CFZN over other cephalosporins such as; cefradine, ceftazidime, cefadroxil, cefaclor and cefoperazone, as well as some additives encountered in the pharmaceutical preparations and so these sensors were successfully used for determination of CFZN. A tubular-type detector incorporating a TDMAC based membrane sensor was prepared and used under hydrodynamic mode of operation for continuous CFZN quantification. The tubular-type detector exhibited a concentration range from 0.5-10 mM with a near-Nernstian response (-53.91 mV decade-1). Continuous monitoring of CFZN offers the advantages of simple design, ease of construction and possible applications to small volumes of drug solutions without pre-treatment. The developed sensor was utilized successfully in static and continuous modes of operation for the determination of CFZN in dosage forms. The results obtained were in good agreement with the standard method of CFZN analysis.

Polymeric films composed of mixture of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) are prepared from casting combined solvent (methylene chloride and methanol in 1:1 ratio) containing 8% weight/volume of both polymers (EC to HPC in 1:3 weight ratio). The structural and optical studies of the films are carried out by X-ray diffraction and UV–vis spectrophotometer. The films are polycrystalline structure with an average grain size from 23.15 to 10.79 nm. The possible optical transition in these films is found to be allowed direct transition. The optical band gap energy (Eg) is estimated to be 5.02 eV for HPC–EC plain film and then decreases with increasing the filler content reaching to 4.24 eV for the film filled with maximum Se80Te14Sn6 content of 1 w%. This suggests that Se80Te14Sn6, as filler, is a good choice to control the optical properties of HPC–EC blend film.

Polymeric films composed of mixture of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) are prepared from casting combined solvent (methylene chloride and methanol in 1:1 ratio) containing 8% weight/volume of both polymers (EC to HPC in 1:3 weight ratio). The structural and optical studies of the films are carried out by X-ray diffraction and UV–vis spectrophotometer. The films are polycrystalline structure with an average grain size from 23.15 to 10.79 nm. The possible optical transition in these films is found to be allowed direct transition. The optical band gap energy (Eg) is estimated to be 5.02 eV for HPC–EC plain film and then decreases with increasing the filler content reaching to 4.24 eV for the film filled with maximum Se80Te14Sn6 content of 1 w%. This suggests that Se80Te14Sn6, as filler, is a good choice to control the optical properties of HPC–EC blend film.

Polymeric films composed of mixture of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) are prepared from casting combined solvent (methylene chloride and methanol in 1:1 ratio) containing 8% weight/volume of both polymers (EC to HPC in 1:3 weight ratio). The structural and optical studies of the films are carried out by X-ray diffraction and UV–vis spectrophotometer. The films are polycrystalline structure with an average grain size from 23.15 to 10.79 nm. The possible optical transition in these films is found to be allowed direct transition. The optical band gap energy (Eg) is estimated to be 5.02 eV for HPC–EC plain film and then decreases with increasing the filler content reaching to 4.24 eV for the film filled with maximum Se80Te14Sn6 content of 1 w%. This suggests that Se80Te14Sn6, as filler, is a good choice to control the optical properties of HPC–EC blend film.