Poly (N-isopropylacrylamide) based hydrogels as novel precipitation and stabilization media for solid lipid nanoparticles (SLNs)

Targeted drug delivery using beeswax-derived albendazole-loaded solid lipid nanoparticles in Haemonchus contortus, an albendazole-tolerant nematode

Targeted delivery has not been achieved for anthelmintic treatment, resulting in the requirement of excess drug dose leading to side effects and therapeutic resistance. Gastrointestinal helminths take up lipid droplets from digestive fluid for energy production, egg development, and defense which inspired us to develop biocompatible and orally administrable albendazole-loaded solid lipid nanoparticles (SLN-A) that were derived from beeswax and showed drug loading efficiency of 83.3 ± 6.5 mg/g and sustained-release properties with 84.8 ± 2.5% of drug released at pH 6.4 within 24 h at 37 °C. Rhodamine B-loaded SLN showed time-dependent release and distribution of dye in-vitro in Haemonchus contortus. The sustained-release property was shown by the particles that caused enhancement of albendazole potency up to 50 folds. Therefore, this formulation has immense potential as an anthelminthic drug delivery vehicle that will be able to reduce the dose and drug-induced side effects by enhancing the bioavailability of the drug.

Tuning the thermodynamic, optical, and rheological properties of thermoresponsive polymer solutions via silica nanoparticle shape and concentration

HYPOTHESIS

The shape and quantity of hydrophilic silica nanoparticles (NPs) can be used to tune the microstructure, rheology, and stability of phase-separating polymer solutions. In thermoresponsive polymer systems, silica nanospheres are well-studied whereas anisotropic NPs have little literature precedent. Here, we hypothesize that NP shape and concentration lower the onset of rheological and turbidimetric transitions of aqueous poly(N-isopropyl acrylamide) (PNIPAM) solutions.

EXPERIMENTS

Differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), turbidimetry, and oscillatory rheology are utilized to examine interactions between NPs, PNIPAM, and water and to track changes in phase separation and rheological properties due to NP concentration and shape.

FINDINGS

NP addition reduces phase separation enthalpy due to PNIPAM-NP hydrogen bonding interactions, the degree to which depends on polymer content. While NP addition minorly impacts thermodynamic and optical properties, rheological transitions and associated rheological properties are dramatically altered with increasing temperature, and depend on NP quantity, shape, and polymer molecular weight. Thus NP content and shape can be used to finely tune transition temperatures and mechanical properties for applications in stimuli-responsive materials.

Fabrication, physicochemical characterization and In vitro anticancer activity of nerolidol encapsulated solid lipid nanoparticles in human colorectal cell line

Nerolidol is a sesquiterpene that occurs naturally and possesses a diverse set of biological characteristics including anticancer activity but has limited solubility, bioavailability, and fast hepatic metabolism. The goal of this study was to develop a nanocarrier system encapsulating a bioactive as well as to evaluate its efficacy in Human Colorectal Cell Line. Solid lipid nanoparticles were fabricated by the emulsion solvent evaporation method and determined the particle size, polydispersity index (PDI), zeta potential, % entrapment efficiency, scanning electron microscopy (SEM), transmission electron microscopy (TEM), drug-excipient interaction study of developed nanoparticles. MTT assay was used to assess the cytotoxicity of formulations in vitro. Nerolidol loaded solid lipid nanoparticles (NR-LNPs) have presented satisfactory properties: mean particles diameter of 159 ± 4.89 nm, PDI of 0.32 ± 0.01, the zeta potential value was found to be -10 ± 1.97 and % entrapment efficiency 71.3% ± 6.11. The formulations demonstrated enhanced biological activity due to enhanced solubility and stability of the bioactive after loading into a nanoformulation along with the better internalization inside the cells.

Bioinspired tunable hydrogels: An update on methods of preparation, classification, and biomedical and therapeutic applications

Hydrogels exhibit water-insoluble three-dimensional polymeric networks capable of absorbing large amounts of biological fluids. Both natural and synthetic polymers are used for the preparation of hydrogel networks. Such polymeric networks are fabricated through chemical or physical mechanisms of crosslinking. Chemical crosslinking is accomplished mainly through covalent bonding, while physical crosslinking involves self-healing secondary forces like H-bonding, host-guest interactions, and antigen-antibody interactions. The building blocks of the hydrogels play an important role in determining the mechanical, biological, and physicochemical properties. Hydrogels are used in a variety of biomedical applications like diagnostics (biodetection and bioimaging), delivery of therapeutics (drugs, immunotherapeutics, and vaccines), wound dressing and skin materials, cardiac complications, contact lenses, tissue engineering, and cell culture because of the inherent characteristics like enhanced water uptake and structural similarity with the extracellular matrix (ECM). This review highlights the recent trends and advances in the roles of hydrogels in biomedical and therapeutic applications. We also discuss the classification and methods of hydrogels preparation. A brief outlook on the future directions of hydrogels is also presented.

How does the addition of shape distinct gold nanoparticles influence on the conformational transition of poly(N-isopropylacrylamide)?

HYPOTHESIS

The subject of nanomaterials has created immense interest and expectations in the field of science and nanotechnology. Plentiful aspects proposed by gold nanoparticles (AuNPs) and their capability to affect macromolecular transition is the main driving force to execute the current study. A thermo-responsive polymer poly(N-isopropylacrylamide) (pNIPAM) is studied in presence of nanoparticles, particularly gold nanorods and nanospheres to elucidate completely the effect of their shape, surface area and structural morphology on the conformation of pNIPAM.

EXPERIMENTS

In this respect, several biophysical techniques such as fluorescence spectroscopy, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) are utilized to examine the interaction of Au nanospheres/nanorods with pNIPAM. For a better understanding of Au nanoparticles morphology, transmission electron microscopy (TEM) is also employed.

FINDINGS

Introducing gold nanoparticles with the polymeric solution promotes the polymer to stay in the coil conformation at a higher temperature than the LCST of aqueous pNIPAM. A shift of 2 and 25.5 °C in the LCST of pNIPAM is observed along with Au nanospheres and nanorods, respectively. The current study provides a better impact in the field of biomedical science specifically drug delivery and tissue engineering as the LCST approaches human body temperature.