Magnetic dual-responsive semi-IPN nanogels based on chitosan/PNVCL and study on BSA release behavior

Albumin-loaded thermo/pH dual-responsive nanogels based on sodium alginate and poly (N-vinyl caprolactam)

During the past decades, many researchers have tried to encapsulate medicines in biopolymer nanogels as injectable medicines. In the present study, dual-responsive bovine serum albumin (BSA)-loaded nanogels prepared from sodium alginate grafted poly (N-vinyl caprolactam) (PNVCL) have been reported. First, PNVCL-g-sodium alginate (PNVCL-g-Alg) was synthesized through free radical polymerization, and then nanogels were obtained from ionic crosslinking of sodium alginate in the presence of BSA. FTIR spectra showed that PNVCL-g-Alg nanogels were successfully prepared. Turbidimetry and rheometry analyses demonstrated the cloud point temperature near the human body. Particle size was evaluated using FE-SEM and dynamic light scattering and it was found that the size of particles in dry and swollen state are about 30 and 280 nm, respectively. The effect of temperature and pH on BSA release was evaluated. By comparing the drug release behavior, we found that the release of the protein at the temperature above the cloud point is faster than that at the temperature below the cloud point. The pH sensitivity of BSA-loaded PNVCL-g-Alg was evaluated at pH 5.5 and 7.4 and showed that the drug release was faster at acidic pH than at neutral pH.

Magnetic Nanoparticles: Current Advances in Nanomedicine, Drug Delivery and MRI

Magnetic nanoparticles (MNPs) have evolved tremendously during recent years, in part due to the rapid expansion of nanotechnology and to their active magnetic core with a high surface-to-volume ratio, while their surface functionalization opened the door to a plethora of drug, gene and bioactive molecule immobilization. Taming the high reactivity of the magnetic core was achieved by various functionalization techniques, producing MNPs tailored for the diagnosis and treatment of cardiovascular or neurological disease, tumors and cancer. Superparamagnetic iron oxide nanoparticles (SPIONs) are established at the core of drug-delivery systems and could act as efficient agents for MFH (magnetic fluid hyperthermia). Depending on the functionalization molecule and intrinsic morphological features, MNPs now cover a broad scope which the current review aims to overview. Considering the exponential expansion of the field, the current review will be limited to roughly the past three years.

NVCL-Based Hydrogels and Composites for Biomedical Applications: Progress in the Last Ten Years

Hydrogels consist of three-dimensionally crosslinked polymeric chains, are hydrophilic, have the ability to absorb other molecules in their structure and are relatively easy to obtain. However, in order to improve some of their properties, usually mechanical, or to provide them with some physical, chemical or biological characteristics, hydrogels have been synthesized combined with other synthetic or natural polymers, filled with inorganic nanoparticles, metals, and even polymeric nanoparticles, giving rise to composite hydrogels. In general, different types of hydrogels have been synthesized; however, in this review, we refer to those obtained from the thermosensitive polymer poly(N-vinylcaprolactam) (PNVCL) and we focus on the definition, properties, synthesis techniques, nanomaterials used as fillers in composites and mainly applications of PNVCL-based hydrogels in the biomedical area. This type of material has great potential in biomedical applications such as drug delivery systems, tissue engineering, as antimicrobials and in diagnostic and bioimaging.