Effect of surface decoration on properties and drug release ability of nanogels

Stimuli-Responsive and Multifunctional Nanogels in Drug Delivery

Nanogels represent promising drug delivery systems in the biomedical field, designed to overcome challenges associated with standard treatment approaches. Stimuli-responsive nanogels, often referred to as intelligent materials, have garnered significant attention for their potential to enhance control over properties such as drug release and targeting. Furthermore, researchers have recently explored the application of nanogels in diverse sectors beyond biomedicine including sensing materials, catalysts, or adsorbents for environmental applications. However, to fully harness their potential as practical delivery systems, further research is required to better understand their pharmacokinetic behaviour, interactions between nanogels and bio distributions, as well as toxicities. One promising future application of stimuli-responsive multifunctional nanogels is their use as delivery agents in cancer treatment, offering an alternative to overcome the challenges with conventional approaches. This review discusses various synthetic methods employed in developing nanogels as efficient carriers for drug delivery in cancer treatment. The investigations explore, the key aspects of nanogels, including their multifunctionality and stimuli-responsive properties, as well as associated toxicity concerns. The discussions presented herein aim to provide the readers a comprehensive understanding of the potential of nanogels as smart drug delivery systems in the context of cancer therapy.

CuAAC ensembled 1,2,3-triazole linked nanogels for targeted drug delivery: a review

Copper(i) catalyzed alkyne azide cycloaddition (CuAAC), the quintessential example of 'click chemistry', provides an adaptable and adequate platform for the synthesis of nanogels for sustained drug release at targeted sites because of their better biocompatibility. The coupling of drugs, carried out via various synthetic routes including CuAAC, into long-chain polymeric forms like nanogels has exhibited considerable assurance in therapeutic advancements and intracellular drug delivery due to the progression of water solubility, evacuation of precocious drug release, and improved upthrust of the pharmacokinetics of the nanogels, thereby rendering them as better and efficient drug carriers. The inefficiency of drug transmission to the target areas due to the resistance of complex biological barriers in vivo is a major hurdle that impedes the therapeutic translation of nanogels. This review compiles the data of nanogels synthesized specifically via CuAAC 'click' methodology, as scaffolds for targeted drug delivery and their assimilation into nanomedicine. In addition, it elaborates the ability of CuAAC to graft specific moieties and conjugating biomolecules like proteins and growth factors, onto orthogonally functionalized polymer chains with various chemical groups resulting in nanogels that are not only more appealing but also more effective at delivering drugs, thereby enhancing their site-specific target approach and initiating selective therapies.

Biomaterial-Mediated Factor Delivery for Spinal Cord Injury Treatment

Spinal cord injury (SCI) is an injurious process that begins with immediate physical damage to the spinal cord and associated tissues during an acute traumatic event. However, the tissue damage expands in both intensity and volume in the subsequent subacute phase. At this stage, numerous events exacerbate the pathological condition, and therein lies the main cause of post-traumatic neural degeneration, which then ends with the chronic phase. In recent years, therapeutic interventions addressing different neurodegenerative mechanisms have been proposed, but have met with limited success when translated into clinical settings. The underlying reasons for this are that the pathogenesis of SCI is a continued multifactorial disease, and the treatment of only one factor is not sufficient to curb neural degeneration and resulting paralysis. Recent advances have led to the development of biomaterials aiming to promote in situ combinatorial strategies using drugs/biomolecules to achieve a maximized multitarget approach. This review provides an overview of single and combinatorial regenerative-factor-based treatments as well as potential delivery options to treat SCIs.

Preparation and characterization of magnetic nanohydrogel based on chitosan for 5-fluorouracil drug delivery and kinetic study

Chemotherapy is currently used for most cancer treatments, but one of the significant problems of this treatment is that it affects the healthy tissues of the body. Therefore, designing new systems for the intelligent and controlled release of these drugs in cancer tissues is one of the major challenges in the world. Hence, today, huge costs are spent designing appropriate new drug delivery systems (DDS) with controlled drug release. In this study, chitosan-polyacrylic acid encapsulated Fe₃O₄ magnetic nanogelic core-shell (Fe₃O₄@CS-PAA) was synthesized in the presence of glutaraldehyde used for loaded anticancer 5-fluorouracil (5-FU) drug. Also, the prepared Fe₃O₄@CS-PAA was characterized by using FT-IR, SEM, XRD, and VSM analysis. Then, drug delivery tests were carried out in the in-vitro conditions that are the simulated physiological environment and tumor tissue conditions. The drug release tests indicated that the Fe₃O₄@CS-PAA upgraded the rate of 5-FU release from nanogelic core-shell under tumor tissue conditions (pH 4.5) than physiological environments (pH 7.4). In addition, various models were used to investigate the drug release mechanism. Results of modeling studies of drug release showed the mechanism of 5-FU release from Fe₃O₄@CS-PAA controlled by Fickian diffusion.

Formation of Multicolor Nanogels Based on Cationic Polyfluorenes and Poly(methyl vinyl ether-alt-maleic monoethyl ester): Potential Use as pH-Responsive Fluorescent Drug Carriers

In this study, we employed the copolymer poly(methyl vinyl ether-alt-maleic monoethyl ester) (PMVEMA-Es) and three fluorene-based cationic conjugated polyelectrolytes to develop fluorescent nanoparticles with emission in the blue, green and red spectral regions. The size, Zeta Potential, polydispersity, morphology, time-stability and fluorescent properties of these nanoparticles were characterized, as well as the nature of the interaction between both PMVEMA-Es and fluorescent polyelectrolytes. Because PMVEMA-Es contains a carboxylic acid group in its structure, the effects of pH and ionic strength on the nanoparticles were also evaluated, finding that the size is responsive to pH and ionic strength, largely swelling at physiological pH and returning to their initial size at acidic pHs. Thus, the developed fluorescent nanoparticles can be categorized as pH-sensitive fluorescent nanogels, since they possess the properties of both pH-responsive hydrogels and nanoparticulate systems. Doxorubicin (DOX) was used as a model drug to show the capacity of the blue-emitting nanogels to hold drugs in acidic media and release them at physiological pH, from changes in the fluorescence properties of both nanoparticles and DOX. In addition, preliminary studies by super-resolution confocal microscopy were performed, regarding their potential use as image probes.