Double-Network Nanogel as a Nonviral Vector for DNA Delivery

Nanogels as target drug delivery systems in cancer therapy: A review of the last decade

Cancer is an important cause of morbidity and mortality worldwide, irrespective of the level of human development. Globally, it was estimated that there were 19.3 million new cases of cancer and almost 10 million deaths from cancer in 2020. The importance of prevention, early detection as well as effective cancer therapies cannot be over-emphasized. One of the important strategies in cancer therapy is targeted drug delivery to the specific tumor sites. Nanogels are among the several drug delivery systems (DDS) being explored as potential candidates for targeted drug delivery in cancer therapy. Nanogels, which are new generation, versatile DDS with the possession of dual characteristics of hydrogels and nanoparticles have shown great potential as targeted DDS in cancer therapy. Nanogels are hydrogels with a three-dimensional (3D) tunable porous structure and a particle size in the nanometre range, from 20 to 200 nm. They have been visualized as ideal DDS with enormous drug loading capacity, and high stability. Nanogels can be modified to achieve active targeting and enhance drug accumulation in disease sites. They can be designed to be stimulus-responsive, and react to internal or external stimuli such as pH, temperature, light, redox, thus resulting in the controlled release of loaded drug. This prevents drug accumulation in non-target tissues and minimizes the side effects of the drug. Drugs with severe adverse effects, short circulation half-life, and easy degradability by enzymes, such as anti-cancer drugs, and proteins, are suitable for delivery by chemically cross-linked or physically assembled nanogel systems. This systematic review summarizes the evolution of nanogels for targeted drug delivery for cancer therapy over the last decade. On-going clinical trials and recent applications of nanogels as targeted DDS for cancer therapy will be discussed in detail. The review will be concluded with discussions on safety and regulatory considerations as well as future research prospects of nanogel-targeted drug delivery for cancer therapy.

Development of a Polysaccharide-Based Hydrogel Drug Delivery System (DDS): An Update

Delivering a drug to the target site with minimal-to-no off-target cytotoxicity is the major determinant for the success of disease therapy. While the therapeutic efficacy and cytotoxicity of the drug play the main roles, the use of a suitable drug delivery system (DDS) is important to protect the drug along the administration route and release it at the desired target site. Polysaccharides have been extensively studied as a biomaterial for DDS development due to their high biocompatibility. More usefully, polysaccharides can be crosslinked with various molecules such as micro/nanoparticles and hydrogels to form a modified DDS. According to IUPAC, hydrogel is defined as the structure and processing of sols, gels, networks and inorganic–organic hybrids. This 3D network which often consists of a hydrophilic polymer can drastically improve the physical and chemical properties of DDS to increase the biodegradability and bioavailability of the carrier drugs. The advancement of nanotechnology also allows the construction of hydrogel DDS with enhanced functionalities such as stimuli-responsiveness, target specificity, sustained drug release, and therapeutic efficacy. This review provides a current update on the use of hydrogel DDS derived from polysaccharide-based materials in delivering various therapeutic molecules and drugs. We also highlighted the factors that affect the efficacy of these DDS and the current challenges of developing them for clinical use.

Camacho-Cruz L, Bucio E, Kadlubowski SS. An Updated Review of Macro, Micro, and Nanostructured Hydrogels for Biomedical and Pharmaceutical Applications

Hydrogels are materials with wide applications in several fields, including the biomedical and pharmaceutical industries. Their properties such as the capacity of absorbing great amounts of aqueous solutions without losing shape and mechanical properties, as well as loading drugs of different nature, including hydrophobic ones and biomolecules, give an idea of their versatility and promising demand. As they have been explored in a great number of studies for years, many routes of synthesis have been developed, especially for chemical/permanent hydrogels. In the same way, stimuli-responsive hydrogels, also known as intelligent materials, have been explored too, enhancing the regulation of properties such as targeting and drug release. By controlling the particle size, hydrogel on the micro- and nanoscale have been studied likewise and have increased, even more, the possibilities for applications of the so-called XXI century materials. In this paper, we aimed to produce an overview of the recent studies concerning methods of synthesis, biomedical, and pharmaceutical applications of macro-, micro, and nanogels.