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

Oligonucleotide based nanogels for cancer therapeutics

Oligonucleotide-based nanogels, as nascent biomaterials, possess several unique functional, structural, and physicochemical features with excellent drug-loading capacity and high potential for cancer gene therapy. Ongoing studies utilizing oligonucleotide-based nanogels hold great promise, as these cutting-edge nanoplatforms can be elegantly developed with predesigned oligonucleotide sequences and complementary strands which are self-assembled or chemically crosslinked leading to the development of nanogels with predictable shape and tunable size with the desired functional properties. Current paper provides a summary of the properties, preparation methods, and applications of oligonucleotide-based nanogels in cancer therapy. The review is focused on both conventional and modified forms of oligonucleotide-based nanogels, including targeted nanogels, smart release nanogels (responsive to stimuli such as pH, temperature, and enzymes), as well as nanogels used for gene delivery. Their application in cancer immunotherapy and vaccination, photodynamic therapy, and diagnostic applications when combined with other nanoparticles is further discussed. Despite emerging designs in the development of oligonucleotide based nanogels, this field of study is still in its infancy, and clinical translation of these versatile nano-vehicles might face challenges. Hence, extensive research must be performed on in vivo behavior of such platforms determining their biodistribution, biological fate, and acute/subacute toxicity.

Plasmonic nano-bowls for monitoring intra-membrane changes in liposomes, and DNA-based nanocarriers in suspension

Programmable nanoscale carriers, such as liposomes and DNA, are readily being explored for personalized medicine or disease prediction and diagnostics. The characterization of these nanocarriers is limited and challenging due to their complex chemical composition. Here, we demonstrate the utilization of surface-enhanced Raman spectroscopy (SERS), which provides a unique molecular fingerprint of the analytes while reducing the detection limit. In this paper, we utilize a silver coated nano-bowl shaped polydimethylsiloxane (PDMS) SERS substrate. The utilization of nano-bowl surface topology enabled the passive trapping of particles by reducing mobility, which results in reproducible SERS signal enhancement. The biological nanoparticles' dwell time in the nano-trap was in the order of minutes, thus allowing SERS spectra to remain in their natural aqueous medium without the need for drying. First, the geometry of the nano-traps was designed considering nanosized bioparticles of 50-150 nm diameter. Further, the systematic investigation of maximum SERS activity was performed using rhodamine 6 G as a probe molecule. The potential of the optimized SERS nano-bowl is shown through distinct spectral features following surface- (polyethylene glycol) and bilayer- (cholesterol) modification of empty liposomes of around 140 nm diameter. Apart from liposomes, the characterization of the highly crosslinked DNA specimens of only 60 nm in diameter was performed. The modification of DNA gel by liposome coating exhibited unique signatures for nitrogenous bases, sugar, and phosphate groups. Further, the unique sensitivity of the proposed SERS substrate displayed distinct spectral signatures for DNA micelles and drug-loaded DNA micelles, carrying valuable information to monitor drug release. In conclusion, the findings of the spectral signatures of a wide range of molecular complexes and chemical morphology of intra-membranes in their natural state highlight the possibilities of using SERS as a sensitive and instantaneous characterization alternative.

Nanogel-based composites for bacterial antibiofilm activity: advances, challenges, and prospects

Nano-based approaches, particularly nanogels, have recently emerged as a potential strategy for combating biofilm-related infections. Their exceptional characteristics including biocompatibility, biodegradability, stability, high water content, stimuli-responsiveness, and their nano size (which enables their penetration into biofilms) make nanogels a promising technology in the biomedical field. However, exploring nanogels for biofilm treatment remains in its early stages. This review examined the status of nanogels application for the treatment of bacterial biofilms. Recent investigations studied nanogels derived from natural polymers like chitosan (CS), hyaluronic acid (HA), and alginate, among others, for eliminating and inhibiting biofilms. These nanogels were utilized as carriers for diverse antibiofilm agents, encompassing antibiotics, antimicrobial peptides, natural extracts, and nanoparticles. Utilizing mechanisms like conventional antibody-mediated pathways, photodynamic therapy, photothermal therapy, chemodynamic therapy, and EPS degradation, these nanogels effectively administered antibiofilm drugs, exhibiting efficacy across several bacterial strains, notably Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli), among others. Despite showing promise, nanogels remain relatively underexplored in biofilm treatment. This review concludes that research gaps are still present in biofilm treatment processes including (i) a better understanding of the stimuli-responsive behaviors of nanogels, (ii) active targeting strategies, and (iii) the narrow spectrum of antibiofilm agents loaded into nanogels. Hence, future studies could be directed towards the following elements: the exploration of multi-strain biofilms rather than single-strain biofilms, other endogenous and exogenous stimuli to trigger drug release, active targeting mechanisms, a broader range of antibiofilm agents when employing nanogels, and fostering more comprehensive and reliable biofilm treatment strategies. This review found that there are currently several research gaps as well in the use of nanogels for biofilm therapy, and these include: (i) very limited exogenous and endogenous stimuli were explored to trigger drug release from nanogels, (ii) the active targeting strategies were not explored, (iii) a very narrow spectrum of antibiofilm agents was loaded into nanogels, and (iv) only biofilms of single strains were investigated.

Nanogels Based on N,N-Dimethylacrylamide and β-Cyclodextrin Triacrylate for Enhanced Solubility and Therapeutic Efficacy of Aripiprazole

Aripiprazole (ARZ) is a medication used for the treatment of various diseases such as schizophrenia, bipolar disorder, major depressive disorder, autism, and Tourette's syndrome. Despite its therapeutic benefits, ARZ is characterized by a poor water solubility which provoked the development of various delivery systems in order to enhance its solubility. In the present work, a nanoscale drug delivery system based on N,N-dimethylacrylamide (DMAA) and β-cyclodextrin triacrylate (β-CD-Ac3) as potential aripiprazole delivery vehicles was developed. The nanogels were synthesized by free radical polymerization of DMAA in the presence of β-CD-Ac3 as a crosslinking agent and then loaded with ARZ via host-guest inclusion complexation. The blank- and drug-loaded nanogels were evaluated using different methods. Fourier transform infrared (FTIR) spectroscopy was employed to confirm the incorporation of β-CD moieties into the polymer network. Dynamic light scattering (DLS) was used to study the size of the developed systems. The samples exhibited a monomodal particle size distribution and a relatively narrow dispersity index. The hydrodynamic diameter (Dh) of the gels varied between 107 and 129 nm, with a tendency for slightly larger particles as the β-CD-Ac3 fraction increased. Loading the drug into the nanocarrier resulted in slightly larger particles than the blank gels, but their size was still in the nanoscopic range (166 to 169 nm). The release profiles in PBS were studied and a sustained release pattern with no significant burst effect was observed. A cytotoxicity assessment was also conducted to demonstrate the non-toxicity and biocompatibility of the studied polymers.

Nano-therapeutics: The upcoming nanomedicine to treat cancer

Nanotechnology is considered a successful approach for cancer diagnosis and treatment. Preferentially, cancer cell recognition and drug targeting via nano-delivery system include the penetration of anticancer agents into the cell membrane to damage the cancer cell by protein modification, DNA oxidation, or mitochondrial dysfunction. The past research on nano-delivery systems and their target has proven the beneficial achievement in a malignant tumor. Modern perceptions using inventive nanomaterials for cancer management have been offered by a multifunctional platform based on various nano-carriers with the probability of imaging and cancer therapy simultaneously. Emerging nano-delivery systems in cancer therapy still lack knowledge of the biological functions behind the interaction between nanoparticles and cancer cells. Since the potential of engineered nanoparticles addresses the various challenges, limiting the success of cancer therapy subsequently, it is a must to review the molecular targeting of a nano-delivery system to enhance the therapeutic efficacy of cancer. This review focuses on using a nano-delivery system, an imaging system, and encapsulated nanoparticles for cancer therapy.

Agar Graft Modification with Acrylic and Methacrylic Acid for the Preparation of pH-Sensitive Nanogels for 5-Fluorouracil Delivery

Agar, a naturally occurring polysaccharide, has been modified by grafting it with acrylic (AcA) and methacrylic (McA) acid monomers, resulting in acrylic or methacrylic acid grafted polymer (AA-g-AcA or AA-g-McA) with pH-sensitive swelling behavior. Different ratios between agar, monomers, and initiator were applied. The synthesized grades of both new polymer series were characterized using FTIR spectroscopy, NMR, TGA, DSC, and XRD to ascertain the intended grafting. The percentage of grafting (% G), grafting efficiency (% GE), and % conversion (% C) were calculated, and models with optimal characteristics were further characterized. The swelling behavior of the newly synthesized polymers was studied over time and in solutions with different pH. These polymers were subsequently crosslinked with varying amounts of glutaraldehyde to obtain 5-fluorouracil-loaded nanogels. The optimal ratios of polymer, drug, and crosslinker resulted in nearly 80% loading efficiency. The performed physicochemical characterization (TEM and DLS) showed spherical nanogels with nanometer sizes (105.7-250 nm), negative zeta potentials, and narrow size distributions. According to FTIR analysis, 5-fluorouracil was physically incorporated. The swelling and release behavior of the prepared nanogels was pH-sensitive, favoring the delivery of the chemotherapeutic to tumor cells. The biocompatibility of the proposed nanocarrier was proven using an in vitro hemolysis assay.

Nanoparticles loaded withβ-Lapachone and Fe3+exhibit enhanced chemodynamic therapy by producing H2O2through cascaded amplification

The rapid, irreversible change of active Fe2+to inactive Fe3+after the Fenton reaction occurring reduces the chemodynamic therapeutic (CDT) effect. Therefore, manipulation of the tumor microenvironment to provide sufficient hydrogen peroxide (H2O2) while maintaining metal ion catalyst activity is critical for effective CDT. Here,β-Lapachone (LPC) was loaded by mesoporous silica nanoparticles (MSNs) and coated with polydopamine (PDA) to further chelate Fe3+and link aptamer AS1411, and a pH-controlled released, chemotherapy-photothermal therapy (PTT)-enhanced CDT-small molecule therapy combination drug delivery system with passive and active tumor targeting was engineered (designated asβ-LPC@MSN@PDA/Fe3+-AS1411, LMPFA). The results showed that LFMPA nanoparticles massively accumulated in tumor tissues to achieve tumor targeting through AS1411 mediating and enhanced permeability and retention (EPR) effect. Subsequently, PDA released Fe3+and LPC through acid response to exhibited CDT and chemotherapeutic therapy. Meanwhile, the photothermal effect of PDA promoted the release of LPC from the pores of MSN. LPC exerted chemotherapy effect and cyclically producing of H2O2by the catalysis of NQO1, which enhanced the CDT activated by Fe3+. In addition, while serving as a targeted ligand, AS1411 could also exhibit a small molecule therapeutic effect by binding to nucleoli of tumor cells. This unique nano delivery system achieved the combination of chemotherapy, PTT, enhanced CDT and small molecule therapy, and fought against malignant tumors synergistically through multi-target and multi-dimension.

Nano-in-nano enteric protein delivery system: coaxial Eudragit® L100-55 fibers containing poly(N-vinylcaprolactam) nanogels

Oral protein delivery holds significant promise as an effective therapeutic strategy for treating a wide range of diseases. However, effective absorption of proteins faces challenges due to biological barriers such as harsh conditions of the stomach and the low permeability of mucous membranes. To address these challenges, this article presents a novel nano-in-nano platform designed for enteric protein delivery. This platform, obtained by electrospinning, involves a coaxial arrangement comprising poly(N-vinylcaprolactam) nanogels (NGs) enclosed within nanofibers of Eudragit® L100-55 (EU), a pH-responsive polymer. The pH-selective solubility of EU ensures the protection of NGs during their passage through the stomach, where the fibers remain intact at low pH, and releases them in the intestine where EU dissolves. The switchable characteristic of this nano-in-nano platform is confirmed by using NGs loaded with a model protein (ovalbumin), which is selectively released when the intestinal pH is achieved. The versatility of this nano-in-nano delivery platform is demonstrated by the ability to modify the fibers dissolution profile simply by adjusting the concentration of EU used in the electrospinning process. Furthermore, by tuning the properties of NGs, the potential applications of this platform can be further extended, paving the way for diverse therapeutic possibilities.

Recent advances in stimuli-responsive tailored nanogels for cancer therapy; from bench to personalized treatment

To improve the quality of health in a personalized manner, better control over pharmacologically relevant cargo formulation, organ-specific targeted delivery, and on-demand release of therapeutic agents is crucial. Significant work has been put into designing and developing revolutionary nanotherapeutics approaches for the effective monitoring and personalized treatment of disease. Nanogel (NG) has attracted significant interest because of its tremendous potential in cancer therapy and its environmental stimuli responsiveness. NG is considered a next-generation delivery technology due to its benefits like as size tunability, high loading, stimuli responsiveness, prolonged drug release via in situ gelling mechanisms, stability, and its potential to provide personalized therapy from the investigation of human genes and the genes in various types of cancers and its association with a selective anticancer drug. Stimuli-responsive NGs can be used as smart nanomedicines to detect and treat cancer and can be tuned as personalized medicine as well. This comprehensive review article's major objectives include the challenges of NGs' clinical translation for cancer treatment as well as its early preclinical successes and prospects.

3D printed scaffolds based on hyaluronic acid bioinks for tissue engineering: a review

Hyaluronic acid (HA) is widely distributed in human connective tissue, and its unique biological and physicochemical properties and ability to facilitate biological structure repair make it a promising candidate for three-dimensional (3D) bioprinting in the field of tissue regeneration and biomedical engineering. Moreover, HA is an ideal raw material for bioinks in tissue engineering because of its histocompatibility, non-immunogenicity, biodegradability, anti-inflammatory properties, anti-angiogenic properties, and modifiability. Tissue engineering is a multidisciplinary field focusing on in vitro reconstructions of mammalian tissues, such as cartilage tissue engineering, neural tissue engineering, skin tissue engineering, and other areas that require further clinical applications. In this review, we first describe the modification methods, cross-linking methods, and bioprinting strategies for HA and its derivatives as bioinks and then critically discuss the strengths, shortcomings, and feasibility of each method. Subsequently, we reviewed the practical clinical applications and outcomes of HA bioink in 3D bioprinting. Finally, we describe the challenges and opportunities in the development of HA bioink to provide further research references and insights.

Plasmonic porous micro- and nano-materials based on Au/Ag nanostructures developed for photothermal cancer therapy: challenges in clinicalization

Photothermal therapy (PTT) has developed in recent decades as a relatively safe method for the treatment of cancers. Recently, various species of gold and silver (Au and Ag) nanostructures have been developed and investigated to achieve PTT due to their highly localized surface plasmon resonance (LSPR) effect. Concisely, the collective oscillation of electrons on the surface of Au and Ag nanostructures upon exposure to a specific wavelength (depending on their size and shape) and further plasmonic resonance leads to the heating of the surface of these particles. Hence, porous species can be equipped with tiny plasmonic ingredients that add plasmonic properties to therapeutic cargoes. In this case, a precise review of the recent achievements is very important to figure out to what extent plasmonic photothermal therapy (PPTT) by Au/Ag-based plasmonic porous nanomedicines successfully treated cancers with satisfactory biosafety. Herein, we classify the various species of LSPR-active micro- and nano-materials. Moreover, the routes for the preparation of Ag/Au-plasmonic porous cargoes and related bench assessments are carefully reviewed. Finally, as the main aim of this study, principal requirements for the clinicalization of Ag/Au-plasmonic porous cargoes and their further challenges are discussed, which are critical for specialists in this field.

Injectable hydrogels for personalized cancer immunotherapies

The field of cancer immunotherapy has shown significant growth, and researchers are now focusing on effective strategies to enhance and prolong local immunomodulation. Injectable hydrogels (IHs) have emerged as versatile platforms for encapsulating and controlling the release of small molecules and cells, drawing significant attention for their potential to enhance antitumor immune responses while inhibiting metastasis and recurrence. IHs delivering natural killer (NK) cells, T cells, and antigen-presenting cells (APCs) offer a viable method for treating cancer. Indeed, it can bypass the extracellular matrix and gradually release small molecules or cells into the tumor microenvironment, thereby boosting immune responses against cancer cells. This review provides an overview of the recent advancements in cancer immunotherapy using IHs for delivering NK cells, T cells, APCs, chemoimmunotherapy, radio-immunotherapy, and photothermal-immunotherapy. First, we introduce IHs as a delivery matrix, then summarize their applications for the local delivery of small molecules and immune cells to elicit robust anticancer immune responses. Additionally, we discuss recent progress in IHs systems used for local combination therapy, including chemoimmunotherapy, radio-immunotherapy, photothermal-immunotherapy, photodynamic-immunotherapy, and gene-immunotherapy. By comprehensively examining the utilization of IHs in cancer immunotherapy, this review aims to highlight the potential of IHs as effective carriers for immunotherapy delivery, facilitating the development of innovative strategies for cancer treatment. In addition, we demonstrate that using hydrogel-based platforms for the targeted delivery of immune cells, such as NK cells, T cells, and dendritic cells (DCs), has remarkable potential in cancer therapy. These innovative approaches have yielded substantial reductions in tumor growth, showcasing the ability of hydrogels to enhance the efficacy of immune-based treatments. STATEMENT OF SIGNIFICANCE: As cancer immunotherapy continues to expand, the mode of therapeutic agent delivery becomes increasingly critical. This review spotlights the forward-looking progress of IHs, emphasizing their potential to revolutionize localized immunotherapy delivery. By efficiently encapsulating and controlling the release of essential immune components such as T cells, NK cells, APCs, and various therapeutic agents, IHs offer a pioneering pathway to amplify immune reactions, moderate metastasis, and reduce recurrence. Their adaptability further shines when considering their role in emerging combination therapies, including chemoimmunotherapy, radio-immunotherapy, and photothermal-immunotherapy. Understanding IHs' significance in cancer therapy is essential, suggesting a shift in cancer treatment dynamics and heralding a novel period of focused, enduring, and powerful therapeutic strategies.

Rational Design and Development of Polymeric Nanogels as Protein Carriers

Proteins have gained significant attention as potential therapeutic agents owing to their high specificity and reduced toxicity. Nevertheless, their clinical utility is hindered by inherent challenges associated with stability during storage and after in vivo administration. To overcome these limitations, polymeric nanogels (NGs) have emerged as promising carriers. These colloidal systems are capable of efficient encapsulation and stabilization of protein cargoes while improving their bioavailability and targeted delivery. The design of such delivery systems requires a comprehensive understanding of how the synthesis and formulation processes affect the final performance of the protein. This review highlights critical aspects involved in the development of NGs for protein delivery, with specific emphasis on loading strategies and evaluation techniques. For example, factors influencing loading efficiency and release kinetics are discussed, along with strategies to optimize protein encapsulation through protein-carrier interactions to achieve the desired therapeutic outcomes. The discussion is based on recent literature examples and aims to provide valuable insights for researchers working toward the advancement of protein-based therapeutics.

Smart stimuli-responsive polysaccharide nanohydrogels for drug delivery: a review

Polysaccharides have found extensive utilization as biomaterials in drug delivery systems owing to their remarkable biocompatibility, simple functionalization, and inherent biological properties. Within the array of polysaccharide-based biomaterials, there is a growing fascination for self-assembled polysaccharide nanogels (NG) due to their ease of preparation and enhanced appeal across diverse biomedical appliances. Nanogel (or nanohydrogel), networks of nanoscale dimensions, are created by physically or chemically linking polymers together and have garnered immense interest as potential carriers for delivering drugs due to their favorable attributes. These include biocompatibility, high stability, the ability to adjust particle size, the capacity to load drugs, and their inherent potential to modify their surface to actively target specific cells or tissues via the attachment of ligands that can recognize corresponding receptors. Nanogels can be engineered to respond to specific stimuli, such as pH, temperature, light, or redox conditions, allowing controlled release of the encapsulated drugs. This intelligent targeting capability helps prevent drug accumulation in unintended tissues and reduces the potential side effects. Herein, an overview of nanogels is offered, comprising their methods of preparation and the design of stimulus-responsive nanogels that enable controlled release of drugs in response to specific stimuli.

Nanoparticle-based delivery systems as emerging therapy in retinoblastoma: recent advances, challenges and prospects

Retinoblastoma is the most common intraocular malignancy in children. The treatment of this rare disease is still challenging in developing countries due to delayed diagnosis. The current therapies comprise mainly surgery, radiotherapy and chemotherapy. The adverse effects of radiation and chemotherapeutic drugs have been reported to contribute to the high mortality rate and affect patients' quality of life. The systemic side effects resulting from the distribution of chemotherapeutic drugs to non-cancerous cells are enormous and have been recognized as one of the reasons why most potent anticancer compounds fail in clinical trials. Nanoparticulate delivery systems have the potential to revolutionize cancer treatment by offering targeted delivery, enhanced penetration and retention effects, increased bioavailability, and an improved toxicity profile. Notwithstanding the plethora of evidence on the beneficial effects of nanoparticles in retinoblastoma, the clinical translation of this carrier is yet to be given the needed attention. This paper reviews the current and emerging treatment options for retinoblastoma, with emphasis on recent investigations on the use of various classes of nanoparticles in diagnosing and treating retinoblastoma. It also presents the use of ligand-conjugated and smart nanoparticles in the active targeting of anticancer and imaging agents to the tumour cells. In addition, this review discusses the prospects and challenges in translating this nanocarrier into clinical use for retinoblastoma therapy. This review may provide new insight for formulation scientists to explore in order to facilitate the development of more effective and safer medicines for children suffering from retinoblastoma.

A review of FDA approved drugs and their formulations for the treatment of breast cancer

Breast cancer is one of the most diagnosed solid cancers globally. Extensive research has been going on for decades to meet the challenges of treating solid tumors with selective compounds. This article aims to summarize the therapeutic agents which are either being used or are currently under approval for use in the treatment or mitigation of breast cancer by the US FDA, to date. A structured search of bibliographic databases for previously published peer-reviewed research papers on registered molecules was explored and data was sorted in terms of various categories of drugs used in first line/adjuvant therapy for different stages of breast cancer. We included more than 300 peer-reviewed papers, including both research and reviews articles, in order to provide readers an useful comprehensive information. A list of 39 drugs are discussed along with their current status, dose protocols, mechanism of action, pharmacokinetics, possible side effects, and marketed formulations. Another interesting aspect of the article included focusing on novel formulations of these drugs which are currently in clinical trials or in the process of approval. This exhaustive review thus shall be a one-stop solution for researchers who are working in the areas of formulation development for these drugs.

Antitumor activity of 5-fluorouracil polymeric nanogel synthesized by gamma radiation on a rat model of colon carcinoma: a proposed mechanism

The use of 5-fluorouracil (5-FU) is associated with multifaceted challenges and poor pharmacokinetics. Accordingly, our study was designed to prepare 5-FU nanogel as a new form of the colon cancer chemotherapeutic drug 5-FU using polyacrylic acid and gelatin hybrid nanogel as efficient drug carriers. Alongside the in vivo chemotherapeutic evaluation, the anti-proliferative and anti-apoptotic efficacy were carried out for 5-FU nanogel against 1,2-dimethylhydrazine (DMH, 20 mg/kg) and γ-radiation (4 Gy)-prompted colon dysplasia in rats compared to 5-FU. The morphology and size of 5-FU nanogel were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS) in addition to cytotoxicity assay. The expression of phosphoinositide-3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR); Toll-like receptor2 (TLR2)/nuclear factor kappa B), adenosine monophosphate (AMP)-activated protein kinase (AMPK) and its downstream autophagy-related genes in addition to apoptotic markers were measured in colon tissues. Results: 5-FU nanogel reduced the levels of the TLR2/ NF-κβ as well as the expression of PI3K/AKT/mTOR. Moreover, it promoted autophagy through the activation of the AMPK and its downstream targets which consequently augmented the intrinsic and extrinsic apoptotic pathways. Conclusion: Collectively, these data might strengthen the therapeutic potential of 5-FU nanogel which can be used as an antitumor product for colon cancer.

Therapeutic potential and limitations of curcumin as antimetastatic agent

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

Nano-Gels: Recent Advancement in Fabrication Methods for Mitigation of Skin Cancer

In the 21st century, melanoma and non-melanoma skin cancers have become an epidemic outbreak worldwide. Therefore, the exploration of all potential preventative and therapeutic measures based on either physical or bio-chemical mechanisms is essential via understanding precise pathophysiological pathways (Mitogen-activated protein kinase, Phosphatidylinositol 3-kinase Pathway, and Notch signaling pathway) and other aspects of such skin malignancies. Nano-gel, a three-dimensional polymeric cross-linked porous hydrogel having a diameter of 20-200 nm, possesses dual properties of both hydrogel and nanoparticle. The capacity of high drug entrapment efficiency with greater thermodynamic stability, remarkable solubilization potential, and swelling behavior of nano-gel becomes a promising candidate as a targeted drug delivery system in the treatment of skin cancer. Nano-gel can be either synthetically or architectonically modified for responding to either internal or external stimuli, including radiation, ultrasound, enzyme, magnetic, pH, temperature, and oxidation-reduction to achieve controlled release of pharmaceuticals and several bio-active molecules such as proteins, peptides, genes via amplifying drug aggregation in the active targeted tissue and reducing adverse pharmacological effects. Several drugs, such as anti-neoplastic biomolecules having short biological half-lives and prompt enzyme degradability capacity, must be appropriate for administration employing either chemically bridged or physically constructed nano-gel frameworks. The comprehensive review summarizes the advancement in the preparation and characterization methods of targeted nano-gel with enhanced pharmacological potential and preserved intracellular safety limits for the mitigation of skin malignancies with a special emphasize on skin cancer inducing pathophysiological pathways and prospective research opportunities for skin malignancy targeted nano-gels.

Recent Advances in Hydrogel-Based Phototherapy for Tumor Treatment

Phototherapeutic agent-based phototherapies activated by light have proven to be safe modalities for the treatment of various malignant tumor indications. The two main modalities of phototherapies include photothermal therapy, which causes localized thermal damage to target lesions, and photodynamic therapy, which causes localized chemical damage by generated reactive oxygen species (ROS). Conventional phototherapies suffer a major shortcoming in their clinical application due to their phototoxicity, which primarily arises from the uncontrolled distribution of phototherapeutic agents in vivo. For successful antitumor phototherapy, it is essential to ensure the generation of heat or ROS specifically occurs at the tumor site. To minimize the reverse side effects of phototherapy while improving its therapeutic performance, extensive research has focused on developing hydrogel-based phototherapy for tumor treatment. The utilization of hydrogels as drug carriers allows for the sustained delivery of phototherapeutic agents to tumor sites, thereby limiting their adverse effects. Herein, we summarize the recent advancements in the design of hydrogels for antitumor phototherapy, offer a comprehensive overview of the latest advances in hydrogel-based phototherapy and its combination with other therapeutic modalities for tumor treatment, and discuss the current clinical status of hydrogel-based antitumor phototherapy.

Application of injectable hydrogels in cancer immunotherapy

Immunotherapy is a revolutionary and promising approach to cancer treatment. However, traditional cancer immunotherapy often has the disadvantages of limited immune response rate, poor targeting, and low treatment index due to systemic administration. Hydrogels are drug carriers with many advantages. They can be loaded and transported with immunotherapeutic agents, chemical anticancer drugs, radiopharmaceuticals, photothermal agents, photosensitizers, and other therapeutic agents to achieve controlled release of drugs, extend the retention time of drugs, and thus successfully trigger anti-tumor effects and maintain long-term therapeutic effects after administration. This paper reviews recent advances in injectable hydrogel-based cancer immunotherapy, including immunotherapy alone, immunotherapy with combination chemotherapy, radiotherapy, phototherapy, and DNA hydrogel-based immunotherapy. Finally, we review the potential and limitations of injectable hydrogels in cancer immunotherapy.

Targeted Delivery Strategies of Herbal-Based Nanogels: Advancements and Applications

The objective of this review is to thoroughly investigate herbal nano gels as a promising drug delivery approach for the management of various chronic and acute disorders. Herbal nano gels are a novel and promising drug delivery technique, offering special benefits for better therapeutic efficacy. This review offers a comprehensive analysis of the herbal nano gels with a particular emphasis on their evaluation concerning conventional dosage forms, polymer selection criteria, drug release mechanisms, and applications. The comparison study demonstrates that herbal nano gels have different benefits over conventional dose forms. In the areas of oral administration for improved bioavailability and targeted delivery to the gastrointestinal tract, topical drug delivery for dermatological conditions, and targeted delivery strategies for the site-specific treatment of cancer, inflammatory diseases, and infections, they demonstrate encouraging results in transdermal drug delivery for systemic absorption. A promising platform for improved medication delivery and therapeutic effectiveness is provided by herbal nanogels. Understanding drug release mechanisms further contributes to the controlled and sustained delivery of herbal therapeutics. Some of the patents are discussed and the comparative analysis showcases their superiority over conventional dosage forms, and the polymer selection criteria ensure the design of efficient and optimized formulations. Herbal-based nano gels have become a potential approach for improving drug administration. They provide several advantages such as better stability, targeted delivery, and controlled release of therapeutic components. Herbal nano gels are a promising therapeutic approach with the ability to combat a wide range of conditions like cancer, wound healing and also improve patient compliance.