A novel stimuli-responsive magnetic hydrogel based on nature-inspired tragacanth gum for chemo/hyperthermia treatment of cancerous cells

Thermal-responsive β-cyclodextrin-based magnetic hydrogel as a de novo nanomedicine for chemo/hyperthermia treatment of cancerous cells

A novel thermal-responsive β-cyclodextrin-based magnetic hydrogel [β-cyclodextrin-graft-poly(N-isopropylacrylamide)/Fe3O4 (β-CD-g-PNIPAAm/Fe3O4)] was fabricated as a novel nanomedicine for chemo/hyperthermia treatment of cancer cells. Firstly, β-CD was modified by maleic anhydride (MA) followed by copolymerization with NIPAAm monomer and thiol-end capped Fe3O4 nanoparticles (NPs) in the presence of a crosslinker through acrylamide-thiol polymerization system to afford a magnetic hydrogel. The saturation magnetization (δ s) value for developed hydrogel was determined to be 8.2 emu g-1. The hydrogel was physically loaded with an anticancer agent, doxorubicin hydrochloride (Dox). The encapsulation efficiency (EE) of drug into the hydrogel was obtained as 73 %. The system represented acceptable thermal-triggered drug release behavior that best fitted with Higuchi model, demonstrating the release of drug is mostly controlled by diffusion mechanism. The anticancer performance of the β-CD-g-PNIPAAm/Fe3O4-Dox was evaluated using MCF7 cells by MTT-assay. In addition, flow cytometry analyses showed considerable cellular uptake of Dox in the cells treated with β-CD-g-PNIPAAm/Fe3O4-Dox (∼70 %) compared to free Dox (∼28 %). As results, in time period of 48 h by combination of chemo- and hyperthermia-therapies, the developed system displayed greater anticancer efficiency than the free Dox.

Nanotechnology-mediated photodynamic therapy: Focus on overcoming tumor hypoxia

The oxygen level in the tumor is a critical marker that determines response to different treatments. Cancerous cells can adapt to hypoxia and low pH conditions within the tumor microenvironment (TME) to regulate tumor metabolism, proliferation, and promote tumor metastasis as well as angiogenesis, consequently leading to treatment failure and recurrence. In recent years, widespread attempts have been made to overcome tumor hypoxia through different methods, such as hyperbaric oxygen therapy (HBOT), hyperthermia, O2 carriers, artificial hemoglobin, oxygen generator hydrogels, and peroxide materials. While oxygen is found to be an essential agent to improve the treatment response of photodynamic therapy (PDT) and other cancer treatment modalities, the development of hypoxia within the tumor is highly associated with PDT failure. Recently, the use of nanoparticles has been a hot topic for researchers and exploited to overcome hypoxia through Oxygen-generating hydrogels, O2 nanocarriers, and O2 -generating nanoparticles. This review aimed to discuss the role of nanotechnology in tumor oxygenation and highlight the challenges, prospective, and recent advances in this area to improve PDT outcomes. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Enzymatically crosslinked magnetic starch-grafted poly(tannic acid) hydrogel for "smart" cancer treatment: An in vitro chemo/hyperthermia therapy study

A novel strategy was designed and developed based of horseradish peroxidase (HRP)-mediated crosslinking of tyramine-functionalized starch (Tyr-St), tannic acid (TA) and phenolated-magnetic nanoparticles (Fe3O4-PhOH NPs), and simultaneous loading of doxorubicin hydrochloride (Dox) to afford a pH-responsive magnetic hydrogel-based drug delivery system (DDS) for synergistic in vitro chemo/hyperthermia therapy of human breast cancer (MCF-7) cells. The developed St-g-PTA/Fe3O4 magnetic hydrogel showed porous micro-structure with saturation magnetization (δs) value of 19.2 emu g-1 for Fe3O4 NPs content of ∼7.4 wt%. The pore sizes of the St-g-PTA/Fe3O4 hydrogel was calculated to be 2400 ± 200 nm-2. In vitro drug release experiments exhibited the developed DDS has pH-dependent drug release behavior, while at physiological pH (7.4) released only 30 % of the loaded drug after 100 h. Human serum albumin (HSA) adsorption capacities of the synthesized St/Fe3O4 and St-g-PTA/Fe3O4 magnetic hydrogels were obtained as 86 ± 2.2 and 77 ± 1.9 μgmg-1, respectively. The well-known MTT-assay approved the cytocompatibility of the developed St-g-PTA/Fe3O4 hydrogel, while the Dox-loaded system exhibited higher anti-cancer activity than those of the free Dox as verified by MTT-assay, and optical as well as florescent microscopies imaging. The synergistic chemo/hyperthermia therapy effect was also verified for the developed St-g-PTA/Fe3O4-Dox via hot water approach.

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.

Recent advances in adsorption of environmental pollutants using metal-organic frameworks-based hydrogels

Water pollution is increasing significantly owing to industrialization and population growth that lead to serious environmental and health issues. Therefore, the design and development of more effective wastewater treatment approaches are necessary due to a significant upsurge in demand for freshwater. More recently, metal-organic frameworks (MOFs) have attracted attention in environmental science owing to their tunable porosity, unique structure, flexibility, and various composition. Despite these attractive advantages, some drawbacks, including intrinsic fragility, unsatisfied processability, dust formation, and poor reusability, have greatly limited their applications. Therefore, MOFs are often designed as supported-based MOFs (e.g., MOFs-coated composites) or 3D structured composites, such as MOFs-based hydrogels. MOFs-based hydrogels are excellent candidates in the sorption process because of their appropriate adsorption capacity, porous structure, good mechanical properties, durability as well as biodegradable features. In this review, the removal of different pollutants (e.g., synthetic dyes, phosphates, heavy metals, antibiotics, and some organic compounds) from aqueous media has been studied by the adsorption process using MOFs-based hydrogels. The important advancements in the fabrication of MOFs-based hydrogels and their capacities in the adsorption of pollutants under experimental conditions have been discussed. Finally, problems and future perspectives on the adsorption process using MOFs-based hydrogels have been investigated.

Bioinspired Hydrogels as Platforms for Life-Science Applications: Challenges and Opportunities

Hydrogels, as interconnected networks (polymer mesh; physically, chemically, or dynamic crosslinked networks) incorporating a high amount of water, present structural characteristics similar to soft natural tissue. They enable the diffusion of different molecules (ions, drugs, and grow factors) and have the ability to take over the action of external factors. Their nature provides a wide variety of raw materials and inspiration for functional soft matter obtained by complex mechanisms and hierarchical self-assembly. Over the last decade, many studies focused on developing innovative and high-performance materials, with new or improved functions, by mimicking biological structures at different length scales. Hydrogels with natural or synthetic origin can be engineered as bulk materials, micro- or nanoparticles, patches, membranes, supramolecular pathways, bio-inks, etc. The specific features of hydrogels make them suitable for a wide variety of applications, including tissue engineering scaffolds (repair/regeneration), wound healing, drug delivery carriers, bio-inks, soft robotics, sensors, actuators, catalysis, food safety, and hygiene products. This review is focused on recent advances in the field of bioinspired hydrogels that can serve as platforms for life-science applications. A brief outlook on the actual trends and future directions is also presented.