Camptothecin@HMSNs/thermosensitive hydrogel composite for applications in preventing local breast cancer recurrence

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

ROS-responsive thermosensitive polypeptide hydrogels for localized drug delivery and improved tumor chemoimmunotherapy

In this study, we developed a ROS-responsive thermosensitive poly(ethylene glycol)-polypeptide hydrogel loaded with a chemotherapeutic drug, doxorubicin (Dox), an antiviral imidazoquinoline, resiquimod (R848), and antibody targeting programmed cell death protein 1 (aPD-1) for local chemoimmunotherapy. The hydrogel demonstrated controllable degradation and sustained drug release behavior according to the concentration of ROS in vitro. Following intratumoral injection into mice bearing B16F10 melanoma, the Dox/R848/aPD-1 co-loaded hydrogel effectively inhibited tumor growth, prolonged animal survival time and promoted anti-tumor immune responses with low systemic toxicity. In the postoperative model, the Dox/R848/aPD-1 co-loaded hydrogel exhibited enhanced tumor recurrence prevention and long-term immune memory effects. Thus, the hydrogel-based local chemoimmunotherapy system demonstrates potential for effective anti-tumor treatment and suppression of tumor recurrence.

Sustained co-delivery of 5-fluorouracil and cis-platinum via biodegradable thermo-sensitive hydrogel for intraoperative synergistic combination chemotherapy of gastric cancer

Gastric cancer is the fifth most common cancer and the third leading cause of cancer death worldwide, posing a severe threat to human health. Surgical resection remains the most preferred option for gastric cancer treatment. However, for advanced gastric cancer, the curative effect of surgical resection is usually limited by the local recurrence, peritoneal carcinomatosis, or distal metastasis. Intraoperative chemotherapy is an attractive in situ adjuvant treatment strategy to reduce the recurrence and metastasis after surgical resection. Here, we designed a 5-fluorouracil (5-FU) and cis-platinum (DDP) co-delivery system based on a biodegradable temperature-sensitive hydrogel (PDLLA-PEG-PDLLA, PLEL) for intraoperative adjuvant combination chemotherapy of gastric cancer. This 5-FU + DDP/PLEL hydrogel system characterized by a special sol-gel phase transition in response to physiological temperature and presented sustained drug release in vitro and in vivo. A strong synergistic cell proliferation inhibition and apoptosis promotion of 5-FU + DDP/PLEL were observed against gastric cancer MKN45-luc cells. After intraperitoneal injection, the dual-drug loaded hydrogel formulation showed superior anti-tumor effects than the single-drug carrying hydrogels and combination of free 5-FU and DDP on the gastric cancer peritoneal carcinomatosis model. The use of hydrogel for dual-drug delivery had benefited to fewer side effects as well. What's more, we established a mouse model for postsurgical residual tumors and peritoneal carcinomatosis of gastric cancer, in which the intraoperative administration of 5-FU + DDP/PLEL also remarkably inhibited the local recurrence of the orthotopic tumors and the growth of the abdominal metastatic tumors, resulting in an extended lifetime. Hence, this developed dual-drug loaded hydrogel system has great potential in the intraoperative chemotherapy of gastric cancer, that suggests a clinically-relevant and valuable option for postsurgical management of gastric cancer.

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Intraoperative chemotherapy could reduce the recurrence and metastasis after surgical resection of gastroenteric tumors.

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5-FU and DDP co-delivery system based on PLEL was developed for intraoperative combination chemotherapy of gastric cancer.

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This dual-drug loaded hydrogel helped to improve synergistic anti-tumor effects and reduce adverse side effects in vivo.

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5-FU+DDP/PLEL could inhibit recurrence of orthotopic tumors and growth of abdominal metastatic tumors in gastric cancer.

Nanozyme hydrogel for enhanced alkyl radical generation and potent antitumor therapy

Alkyl radicals (R˙), which do not rely on oxygen generation for causing cellular stress, have been applied in tumor treatment, but a large amount of glutathione (GSH) in the tumor cells reacts with alkyl radicals, thereby reducing their antitumor effect. In this study, an enhanced alkyl radical generation system responsive to near-infrared light was designed. The alkyl radical trigger 2,2'-azobis[2-(2-imidazolin-2-yl)propane]-dihydrochloride (AIPH) and nanozyme pyrite (FeS2) were encapsulated in agarose hydrogel to prepare the AIPH-FeS2-hydrogel (AFH) system. FeS2 can be used as a photothermal agent to convert near-infrared light energy into heat energy, leading to the dissolution of the hydrogel. AIPH is simultaneously induced to produce alkyl radicals. FeS2 can also be used as an oxidative stress amplifier to reduce intracellular GSH content, thereby boosting the therapeutic effect of alkyl radicals. Eventually, the oxygen-independent free radicals generated by the AFH system under near-infrared laser irradiation and photothermal treatment can kill cancer cells through the synergistic oxidation/photothermal effect. The AFH system developed herein provides new insights into enhancing the therapeutic effect of alkyl radicals.

Thermosensitive Hydrogels and Advances in Their Application in Disease Therapy

Thermosensitive hydrogels, having unique sol–gel transition properties, have recently received special research attention. These hydrogels exhibit a phase transition near body temperature. This feature is the key to their applications in human medicine. In addition, hydrogels can quickly gel at the application site with simple temperature stimulation and without additional organic solvents, cross-linking agents, or external equipment, and the loaded drugs can be retained locally to improve the local drug concentration and avoid unexpected toxicity or side effects caused by systemic administration. All of these features have led to thermosensitive hydrogels being some of the most promising and practical drug delivery systems. In this paper, we review thermosensitive hydrogel materials with biomedical application potential, including natural and synthetic materials. We describe their structural characteristics and gelation mechanism and briefly summarize the mechanism of drug release from thermosensitive hydrogels. Our focus in this review was to summarize the application of thermosensitive hydrogels in disease treatment, including the postoperative recurrence of tumors, the delivery of vaccines, the prevention of postoperative adhesions, the treatment of nervous system diseases via nasal brain targeting, wound healing, and osteoarthritis treatment.

A biotin-modified and H2O2-activatable theranostic nanoplatform for enhanced photothermal and chemical combination cancer therapy

Although synergistic effects of photothermal therapy (PTT) and chemotherapy for cancer have been extensively investigated in previous studies, more potential strategies need to be exploited to alleviate severe adverse effects. In this study, a biotin-modified and activatable nanotheranostic system is developed. This system (BPSP/DOX-CyBA) composed of H₂O₂-sensitive thioketal (TK) linker, hydrophilic biotin-decorated polyethylene glycol (PEG) segment, hydrophobic polycaprolactone (PCL) segment, could self-assemble into (99±1.3) nm nanoparticles and co-deliver H₂O₂-triggered photosensitizer CyBA and cytotoxic drugs DOX to tumor site. In vitro, DOX and CyBA could release rapidly from nanoparticles, CyBA accumulation in the mitochondria causes mitochondrial damage, leading to mitochondrial dysfunctions,while rising the level of ROS in B16F10 cells, and further to promote the micells to trigger release. CyBA could be activated into CyOH and the photothermal therapy was turn "off" into "on". In BPSP/DOX-CyBA group, the local temperature within tumor reached 50℃ and cell apoptosis rate reached 68.6% under Laser irradiation(650 nm, 1W/cm2). Fluorescence microscopy and flow cytometry analysis further demonstrated the better uptake efficiency on B16F10 cells with biotin decoration. In a mice B16F10 tumor model, the group with co-delivery CyBA and DOX had the best tumor retention effect, the maximal local temperature increasement and the minimum tumor growth with negligible side effects, suggesting the potential of BPSP/DOX-CyBA nanopalteform that synergistic photothermal therapy and chemotherapy and mitochondria damage as an effective melanoma treatment strategy.

Luteolin-Loading Her-2 Nanospheres Enhances Targeting and Therapeutic Effects of Breast Cancer

Despite the broad anticancer activity, whereas the clinical application of luteolin is hindered by unsatisfactory water solubility and non-targeting. Herein, targeted inhibitory effects of luteolin-loading HER2 nanospheres (Her-2-NPs) were successfully prepared by thin film ultrasonic method. In comparison with the non-targeted nanospheres, Her-2 nanospheres could significantly boost the intake of luteolin in SK-BR-3 cells. The proliferation and apoptosis of breast cancer cells were detected by MTT testing and flow cytometry examination, respectively. Consequently, the expressions of FOXO1 mRNA level was detected using qPCR assay and protein level was detected using Westernblot. We discovered that Luteolin-loading Her-2 nanospheres could significantly hinder the proliferation of breast cancer cells, down-regulation their migration, and up-regulation FOXO1 expression at mRNA and protein levels, reveal a mechanism whereby luteolin interferes with breast cancer. Collectively, these results suggest Her-2-modified nanospheres increases the efficiency of luteolin uptake and thus improves the treatment benefit of breast cancer.

Biomaterial-based strategies for maxillofacial tumour therapy and bone defect regeneration

Issues caused by maxillofacial tumours involve not only dealing with tumours but also repairing jaw bone defects. In traditional tumour therapy, the systemic toxicity of chemotherapeutic drugs, invasive surgical resection, intractable tumour recurrence, and metastasis are major threats to the patients' lives in the clinic. Fortunately, biomaterial-based intervention can improve the efficiency of tumour treatment and decrease the possibility of recurrence and metastasis, suggesting new promising antitumour therapies. In addition, maxillofacial bone tissue defects caused by tumours and their treatment can negatively affect the physiological and psychological health of patients, and investment in treatment can result in a multitude of burdens to society. Biomaterials are promising options because they have good biocompatibility and bioactive properties for stimulation of bone regeneration. More interestingly, an integrated material regimen that combines tumour therapy with bone repair is a promising treatment option. Herein, we summarized traditional and biomaterial-mediated maxillofacial tumour treatments and analysed biomaterials for bone defect repair. Furthermore, we proposed a promising and superior design of dual-functional biomaterials for simultaneous tumour therapy and bone regeneration to provide a new strategy for managing maxillofacial tumours and improve the quality of life of patients in the future.

Multiple local therapeutics based on nano-hydrogel composites in breast cancer treatment

The locoregional recurrence of breast cancer after tumor resection represents several clinical challenges, and conventional post-surgical adjuvant therapeutics always bring about significant systemic side effects. Thus, the local therapy strategy has received considerable interest in breast cancer treatment, and hydrogels can function as ideal platforms due to their remarkable properties such as good biocompatibility, biodegradability, flexibility, and multifunctionality. The nano-hydrogel composites can further incorporate the advantages of nanomaterials into the hydrogel system, to fabricate hierarchical structures for stimulating controlled multi-stage release of different therapeutic agents and improving the synergistic effects of combination therapy. In this review, the problems of clinical treatments of breast cancer and properties of hydrogels in current biomedical applications are briefly overviewed. The focus is on recent advances in local therapy based on nano-hydrogel composites for both monotherapy (chemotherapy, photothermal and photodynamic therapy) and combination therapy (dual chemotherapy, photothermal chemotherapy, photothermal immunotherapy, radio-chemotherapy). Moreover, the challenges and perspectives in the development of advanced nano-hydrogel systems are also discussed.

Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems-Synthesis and Characterization

A novel and promising hydrogel drug delivery system (DDS) capable of releasing 5‑fluorouracil (5-FU) in a prolonged and controlled manner was obtained using ε‑caprolactone‑poly(ethylene glycol) (CL-PEG) or rac‑lactide-poly(ethylene glycol) (rac‑LA-PEG) copolymers. Copolymers were synthesized via the ring-opening polymerization (ROP) process of cyclic monomers, ε‑caprolactone (CL) or rac-lactide (rac-LA), in the presence of zirconium(IV) octoate (Zr(Oct)₄) and poly(ethylene glycol) 200 (PEG 200) as catalyst and initiator, respectively. Obtained triblock copolymers were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques; the structure and tacticity of the macromolecules were determined. The relationship between the copolymer structure and the reaction conditions was evaluated. The optimal conditions were specified as 140 °C and 24 h. In the next step, CL-PEG and rac-LA-PEG copolymers were chemically crosslinked using hexamethylene diisocyanate (HDI). Selected hydrogels were subjected to in vitro antitumor drug release studies, and the release data were analyzed using zero-order, first-order, and Korsmeyer-Peppas mathematical models. Controlled and prolonged (up to 432 h) 5-FU release profiles were observed for all examined hydrogels with first-order or zero-order kinetics. The drug release mechanism was generally denoted as non-Fickian transport.

Mesoporous silica nanoparticles: synthesis methods and their therapeutic use-recent advances

Mesoporous silica nanoparticles (MSNPs) are a particular example of innovative nanomaterials for the development of drug delivery systems. MSNPs have recently received more attention for biological and pharmaceutical applications due to their capability to deliver therapeutic agents. Due to their unique structure, they can function as an effective carrier for the delivery of therapeutic agents to mitigate diseases progress, reduce inflammatory responses and consequently improve cancer treatment. The potency of MSNPs for the diagnosis and management of various diseases has been studied. This literature review will take an in-depth look into the properties of various types of MSNPs (e.g. shape, particle and pore size, surface area, pore volume and surface functionalisation), and discuss their characteristics, in terms of cellular uptake, drug delivery and release. MSNPs will then be discussed in terms of their therapeutic applications (passive and active tumour targeting, theranostics, biosensing and immunostimulative), biocompatibility and safety issues. Also, emerging trends and expected future advancements of this carrier will be provided.

Smart Hydrogels - Synthetic Stimuli-Responsive Antitumor Drug Release Systems

Among modern drug formulations, stimuli-responsive hydrogels also called "smart hydrogels" deserve a special attention. The basic feature of this system is the ability to change their mechanical properties, swelling ability, hydrophilicity, bioactive molecules permeability, etc., influenced by various stimuli, such as temperature, pH, electromagnetic radiation, magnetic field and biological factors. Therefore, stimuli-responsive matrices can be potentially used in tissue engineering, cell cultures and technology of innovative drug delivery systems (DDSs), releasing the active substances under the control of internal or external stimuli. Moreover, smart hydrogels can be used as injectable DDSs, due to gel-sol transition connected with in situ cross-linking process. Innovative smart hydrogel DDSs can be utilized as matrices for targeted therapy, which enhances the effectiveness of tumor chemotherapy and subsequently limits systemic toxicity. External stimulus sensitivity allows remote control over the drug release profile and gel formation. On the other hand, internal factors provide drg accumulation in tumor tissue and reduce the concentration of active drug form in healthy tissue. In this report, we summarise the basic knowledge and chemical strategies for the synthetic smart hydrogel DDSs applied in antitumor therapy.