Recent advances in hyaluronic acid-based nanomedicines: Preparation and application in cancer therapy

X-ray triggered scintillator versatile nanocatalytic platform for synergistic photodynamic/chemodynamic therapy

Nanocatalysts with photodynamic therapy (PDT) and chemodynamic therapy (CDT) are excellent for tumor therapy. However, it is still challenging to achieve complete tumor eradication due to the drawbacks of limited penetration depth of intratumoural tissues, hypoxia and complexity of the tumor microenvironment (TME). Herein, we fabricated an integrated multifunctional nanoreactor (LuAG:Tb/Ce-RB@ZIF-8-Au2Pt-HA, LRZAPH) combining scintillating nanoparticles (SCNPs, LuAG:Tb/Ce), a metal-organic framework (ZIF-8), and bimetallic Au2Pt for X-ray-triggered PDT and dual noble-metal nanozyme catalyzed CDT. Such a nanoreactor not only significantly enhanced the PDT effect under X-ray irradiation through full resonance energy transfer from LuAG:Tb/Ce scintillator to Ross Bengal (RB), but also facilitated the reactive oxygen species (ROS) and oxygen (O2) production through the excellent peroxidase-like (POD-like) and catalase-like (CAT-like) catalytic properties of Au2Pt nanozymes. O2 also alleviates hypoxia in intratumoural tissues during coordinated PDT. In addition, the dissociation behavior of ZIF-8 with pH-responsive and targeted of hyaluronic acid (HA) in acidic TME significantly enhanced the therapeutic efficacy of LRZAPH nanocatalysts. Significantly, the high tumor growth inhibition rate of 93 % was revealed due to radiotherapy (RT)/PDT/CDT synergetic therapy in vivo, which minimized the toxic and side effects of conventional clinical radiotherapy/chemotherapy on human. The synergistic effect of LRZAPH nanocatalysts on PDT and catalytically induced CDT is expected to provide new pathways for effective treatment of deep tumors.

A multifunctional hyaluronic acid-engineered mesoporous nanoreactor with H2O2/O2 self-sufficiency for pH-triggered endo-lysosomal escape and synergetic cancer therapy

Monotherapy has poor accuracy and is easily restricted by tumor microenvironment (TME). Remodeling components of the TME to activate multimodal cancer therapy with high precision and efficiency is worth exploring. A multifunctional nanoreactor was fabricated by decorating chlorin e6-modified and PEGylated hyaluronic acid bearing diethylenetriamine-conjugated dihydrolipoic acid on the surface of glucose oxidase (GOx)-loaded hollow mesoporous CuS nanoparticles (labeled as GOx@HCuS@HA). This nanoreactor efficiently targets tumor sites, enhances cellular internalization, and swiftly escapes from endo-lysosomes after intravenous injection. Subsequently, GOx@HCuS@HA was activated in hyaluronidase and H + -rich TME to produce H2O2 and gluconic acid through the oxidation of glucose, which not only blocks the energy supply of cancer cells, executing starvation treatment (ST), but also bolsters hydroxyl radicals (•OH)-based chemodynamic therapy (CDT) by Fenton-like reaction between HCuS and H2O2. Furthermore, reductive Cu ions could catalyze H2O2 to produce O2 to alleviate the limitation of photodynamic therapy (PDT) for tumor hypoxia. Additionally, the photothermal effect of HCuS under NIR irradiation could increase the temperature of tumor tissues to perform photothermal therapy (PTT). This synergistic antitumor strategy could ultimately achieve precise tumor cell destruction and maintain excellent biosafety. Hence, this nanoreactor offer promising prospects for efficient tumor treatment.

Smart Design of Targeted Drug Delivery System for Precise Drug Delivery and Visual Treatment of Brain Gliomas

In the treatment of glioma, which is one of the malignant tumors, although chemotherapy is used as the most common treatment method, it often suffers from low bioavailability. Therefore, improving the precision and efficiency of drugs is crucial in treating gliomas and a great challenge. Here, an advanced drug delivery system is reported for gliomas (CZQD@HA@DOX), which aggregates multiple features such as the susceptible imaging tracer property due to the use of CZQD and the targeting of HA to the receptor cluster 44 (CD44) of glioma cells, which provides the system with the functions of targeted enrichment and precise drug delivery at the tumor site. The pH-responsive drug delivery system has not only an excellent encapsulation rate but also a high drug loading capacity, and the doxorubicin loaded on it can be released centrally at the tumor microenvironment site and causes an increase of reactive oxygen species in the mitochondria and trigger oxidative stress, which leads to high expression of Bax apoptotic proteins, ultimately activating the mitochondrial pathway-mediated apoptotic process in glioma cells. Overall, this drug delivery system has great potential for application in precision targeted therapy and visual tracer imaging of gliomas.

Large Language Model-Assisted Genotoxic Metal-Phenolic Nanoplatform for Osteosarcoma Therapy

Osteosarcoma, a leading primary bone malignancy in children and adolescents, is associated with a poor prognosis and a low global fertility rate. A large language model-assisted phenolic network (LLMPN) platform is demonstrated that integrates the large language model (LLM) GPT-4 into the design of multifunctional metal-phenolic network materials. Fine-tuned GPT-4 identified gossypol as a phenolic compound with superior efficacy against osteosarcoma after evaluating across a library of 60 polyphenols based on the correlation between experimental anti-osteosarcoma activity and multiplexed chemical properties of polyphenols. Subsequently, gossypol is then self-assembled into Cu2+-gossypol nanocomplexes with a hyaluronic acid surface modification (CuGOS NPs). CuGOS NPs has demonstrated the ability to induce genetic alterations and cell death in osteosarcoma cells, offering significant therapeutic benefits for primary osteosarcoma tumors and reducing metastasis without adverse effects on major organs or the genital system. This work presents an LLM-driven approach for engineering metal-organic nanoplatform and broadening applications by harnessing the capabilities of LLMs, thereby improving the feasibility and efficiency of research activities.

Hyaluronic acid regulated facile synthesis of size-tunable multifunctional nanomedicine for effective cancer therapy

The complex and heterogeneous nature of cancer necessitates the development of innovative multifunctional nanomedicines (MN). Hyaluronic acid (HA) is a functional carbohydrate polysaccharide that is widely used in various biomedical fields. In this study, we employed HA as a stabilizer and regulator for the synthesis of a size-tunable nanomedicine comprising ferric ions, doxorubicin, and epigallocatechin gallate (EGCG), referred to as HDE-MN, for cancer therapy. A change in the HA ratio can yield HDE-MNs with sizes varying from ~20 nm to over 100 nm. Modified HA can respond to hyaluronidase (HAase) to provide controllable pH/HAase dual-responsive drug release for improved cancer therapy. Moreover, HA can mediate the targeted delivery of HDE-MNs both in vitro and in vivo to cancer cells. In addition, HDE-MNs reversed multidrug resistance owing to the incorporation of EGCG, inducing ferroptosis due to the involvement of ferric ions. More importantly, HDE-MNs have a photothermal conversion effect, enabling photothermal therapy, photothermally enhanced drug release, and ferroptosis, which collectively contribute to significantly improved cancer therapy. Therefore, the HDE-MNs with laser irradiation achieved full ablation of the in vivo tumors. Together with its good biocompatibility, HDE-MNs may be promising for effective cancer therapy.

Hyaluronic acid application strategies for plant bioactive component delivery: A review

Despite the notable therapeutic effects of bioactive components derived from naturally occurring medicinal plants, various factors such as low solubility, poor bioavailability, possible toxicity, and inadequate tumor targeting capabilities generally hinder their full potential. Hyaluronic Acid (HA), a naturally occurring polysaccharide, has recently attracted significant research interest from scientists owing to its ability to precisely target tumors, anionic polysaccharide properties, and easily modifiable unique structure. In addition to offering a solid backing for delivering plant bioactive constituents, these remarkable attributes also have considerable implications for drug delivery systems in the future. This review delves into HA's application in delivering plant bioactive components, starting with a summary of HA's functional characteristics and detailing its strategies for single and dual-component delivery. The review also provides a forward-looking analysis of the challenges encountered in developing HA-based drug delivery systems.

Harnessing the CD44-targeted delivery of self-assembled hyaluronan nanogel to reverse the antagonism between Cisplatin and Gefitinib in NSCLC cancer therapy

The combination of the standard platinum-based chemotherapy with EGFR-tyrosine kinase inhibitor Gefitinib (Gef) principally boosts the anticancer efficacy of advanced non-small cell lung cancer (NSCLC) through non-overlapping mechanisms of action, however the clinical trials of cisplatin (Cis) and Gef combination failed to show a therapeutic improvement likely due to compromised cellular influx of Cis with the Gef interference. To overcome the antagonism between Cis and Gef in anti-NSCLC therapy, here we demonstrated a self-targeted hyaluronan (HA) nanogel to facilitate the anticancer co-delivery by utilizing the HA's intrinsic targeting towards CD44, a receptor frequently overexpressed on lung cancer cells. The co-assembly between HA, Cis and Gef generated a HA/Cis/Gef nanogel of 177.8 nm, featuring a prolonged drug release. Unlike the Gef inhibited the Cis uptake, the HA/Cis/Gef nanogel efficiently facilitated the drug internalization through CD44-targeted delivery as verified by HA competition and CD44 knocking down in H1975 NSCLC model both in vitro and in vivo. Moreover, the HA/Cis/Gef nanogel significantly improved the anticancer efficacy and meanwhile diminished the side effects in reference to the combination of free Cis and Gef. This CD44-targeted HA/Cis/Gef nanogel provided a potent strategy to advance the platinum-based combination therapy towards optimized NSCLC therapy.

Application of hydrogels for targeting cancer stem cells in cancer treatment

Cancer stem cells (CSCs) are a major hindrance to clinical cancer treatment. Owing to their high tumorigenic and metastatic potential, CSCs are vital in malignant tumor initiation, growth, metastasis, and therapeutic resistance, leading to tumorigenesis and recurrence. Compared with normal tumor cells, CSCs express high levels of surface markers (CD44, CD90, CD133, etc.) and activate specific signaling pathways (Wnt/β-catenin, Notch, and Hedgehog). Although Current drug delivery systems (DDS) precisely target CSCs, the heterogeneity and multidrug resistance of CSCs impede CSC isolation and screening. Conversely, hydrogel DDSs exhibit good biocompatibility and high drug delivery efficiency. Hydrogels are three-dimensional (3D) spatial structures for drug encapsulation that facilitate the controlled release of bioactive molecules. Hence, hydrogels can be loaded with drugs to precisely target CSCs. Their 3D structure can also culture non-CSCs and facilitate their transformation into CSCs. for identification and isolation. Given that their elastic modulus and stiffness characteristics reflect those of the cellular microenvironment, hydrogels can simulate extracellular matrix pathways and markers to regulate CSCs, disrupting the equilibrium between CSC and non-CSC transformation. This article reviews the CSC microenvironment, metabolism, signaling pathway, and surface markers. Additionally, we summarize the existing CSC targeting strategies and explore the application of hydrogels for CSC screening and treatment. Finally, we discuss potential advances in CSC research that may lead to curative measures for tumors through targeted and precise attacks on CSCs.

Targeted delivery of rhein via hyaluronic acid modified liposomes for suppression of growth and metastasis of breast cancer

Targeting and suppressing the malignant growth and metastasis of breast cancer has been challenging for years. Herein, a nanocarrier based on hyaluronic acid (HA)-modified cationic liposomes was developed for targeted delivery of rhein to achieve breast cancer therapy. The optimum HA-Lip-rhein had spherical and core-shell-like morphologies with an appropriate size of 189.7 ± 5.2 nm. Moreover, the HA-Lip-rhein exhibited higher cellular uptake in 4 T1 cells and enhanced cytotoxicity compared with unmodified liposomal rhein. Furthermore, in vitro cell migration and invasion inhibition assays showed that the HA-Lip-rhein exhibited superior inhibitory effects on breast cancer metastasis. HA-Lip-rhein improved the tumor targeting ability, anti-breast cancer activity, with good safety profile in the 4 T1 breast cancer-bearing mice compared with free rhein and Lip-rhein. The appearance of metastatic tumor nodules in the lungs and H&E staining of liver and lung organs confirmed that HA-Lip-rhein exerted strong antitumor efficacy and inhibited distant metastasis of breast cancer. Overall, the developed HA-Lip-rhein exhibited a good antitumor effect and suppression effect of distant metastasis, making it a novel and promising nanoplatform for further development.

Charge reversible hyaluronic acid-based drug delivery system with pH-responsive dissociation for enhanced drug delivery

Improving the efficiency of drug delivery is one of the most important goals in the field of drug delivery. One strategy for drug delivery efficiency is to make the drug delivery system capable of charge reversal. In this study, we used hyaluronic acid (HA) as the skeleton to anchor dimethylmaleic anhydride-modified polylysine (PLL-DMMA) and N-(3-Aminopropyl)-imidazole (IMI) to construct a pH-sensitive (IMI/Zn2+)-HA-PLL-DMMA system via Zn coordination. The (IMI/Zn2+)-HA-PLL-DMMA system can detach DMMA moieties and expose PLL with a positive charge in the acidic tumor microenvironment (TME), which enhances cellular uptake in cancer cells through charge reversal. Once the drug-loaded (IMI/Zn2+)-HA-PLL-DMMA enters cancer cells, it specifically responds and disassembles in the acidic TME, resulting in drug release and inhibition of cancer cell viability. The (IMI/Zn2+)-HA-PLL-DMMA system is designed to regulate drug release behavior with Zn2+ and IMI groups as control units. The HA-based system shows synergistic selective drug delivery in suppressing tumor cells and has potential in cancer therapy.

Stabilized, ROS-sensitive β-cyclodextrin-grafted hyaluronic supramolecular nanocontainers for CD44-targeted anticancer drug delivery

Hyaluronic acid (HA)-based tumor microenvironment-responsive nanocontainers are attractive candidates for anticancer drug delivery due to HA's excellent biocompatibility, biodegradability, and CD44-targeting properties. Nevertheless, the consecutive synthesis of stabilized, stealthy, responsive HA-based multicomponent nanomedicines generally requires multi-step preparation and purification procedures, leading to batch-to-batch variation and scale-up difficulties. To develop a facile yet robust strategy for promoted translations, a silica monomer containing a cross-linkable diethoxysilyl unit was prepared to enable in situ crosslinking without any additives. Further combined with the host-guest inclusion complexation between β-cyclodextrin-grafted HA (HA-CD) and ferrocene-functionalized polymers, ferrocene-terminated poly(oligo(ethylene glycol) methyl ether methacrylate (Fc-POEGMA) and Fc-terminated poly(ε-caprolactone)-b-poly(3-(diethoxymethylsilyl)propyl(2-(methacryloyloxy)ethyl) carbamate) (Fc-PCL-b-PDESPMA), a reactive oxygen species (ROS)-sensitive supramolecular polymer construct, Fc-POEGMA/Fc-PCL-b-PDESPMA@HA-CD was readily fabricated to integrate stealthy POEGMA, tumor active targeting HA, and an in situ cross-linkable PDESPMA sequence. Supramolecular amphiphilic copolymers with two different POEGMA contents of 25 wt% (P1) and 20 wt% (P2) were prepared via a simple physical mixing process, affording two core-crosslinked (CCL) micelles via an in situ sol-gel process of ethoxysilyl groups. The P1-based CCL micelles show not only desired colloidal stability against high dilution, but also an intracellular ROS-mimicking environment-induced particulate aggregation that is beneficial for promoted intracellular release of the loaded cargoes. Most importantly, P1-based nanomedicines exhibited greater cytotoxicity in CD44 receptor-positive HeLa cells than that in CD44 receptor-negative MCF-7 cells. Overall, this work developed HA-based nanomedicines with sufficient extracellular colloidal stability and efficient intracellular destabilization properties for enhanced anticancer drug delivery via smart integration of in situ crosslinking and supramolecular complexation.

New Conjugates of Hyaluronic Acid with γ-Cyclodextrin as Sorafenib Carrier in Cancer Cells

In recent years, nanoparticles based on cyclodextrins have been widely investigated, mainly for drug delivery. In this work, we synthesized nanoparticles with a hyaluronic acid backbone (11 kDa and 45 kDa) functionalized with γ-cyclodextrins. We tested sorafenib in the presence of the new hyaluronan-cyclodextrin conjugates in A2780 (ovarian cancer), SK-HeP-1 (adenocarcinoma) and MDA-MB-453 (breast cancer) cell lines. We found that hyaluronan-cyclodextrin conjugates improve the antiproliferative activity of sorafenib. Remarkably, the system based on the 11 kDa hyaluronan conjugate was the most effective and, in the MDA-MB-453 cell line, significantly reduced the IC50 value of sorafenib cells by about 75 %.

Metal nanozymes modulation of reactive oxygen species as promising strategies for cancer therapy

Nanozymes, nanostructured materials emulating natural enzyme activities, exhibit potential in catalyzing reactive oxygen species (ROS) production for cancer treatment. By facilitating oxidative reactions, elevating ROS levels, and influencing the tumor microenvironment (TME), nanozymes foster the eradication of cancer cells. Noteworthy are their superior stability, ease of preservation, and cost-effectiveness compared to natural enzymes, rendering them invaluable for medical applications. This comprehensive review intricately explores the interplay between ROS and tumor therapy, with a focused examination of metal-based nanozyme strategies mitigating tumor hypoxia. It provides nuanced insights into diverse catalytic processes, mechanisms, and surface modifications of various metal nanozymes, shedding light on their role in intra-tumoral ROS generation and applications in antioxidant therapy. The review concludes by delineating specific potential prospects and challenges associated with the burgeoning use of metal nanozymes in future tumor therapies.

Hyaluronic acid-based multifunctional nanoplatform for glucose deprivation-enhanced chemodynamic/photothermal synergistic cancer therapy

We present a hyaluronic acid (HA)-based nanoplatform (CMGH) integrating starvation therapy (ST), chemodynamic therapy (CDT), and photothermal therapy (PTT) for targeted cancer treatment. CMGH fabrication involved the encapsulation of glucose oxidase (GOx) within a copper-based metal-organic framework (CM) followed by surface modification with HA. CMGH exerts its antitumor effects by catalyzing glucose depletion at tumor sites, leading to tumor cell starvation and the concomitant generation of glucuronic acid and H2O2. The decreased pH and elevated H2O2 promote the Fenton-like reaction of Cu ions, leading to hydroxyl radical production. HA modification enables targeted accumulation of CMGH at tumor sites via the CD44 receptor. Under near-infrared light irradiation, CM exhibits photothermal conversion capability, enhancing the antitumor effects of CMGH. In vitro and in vivo studies demonstrate the effective inhibition of tumor growth by CMGH. This study highlights the potential of CMGH as a targeted cancer therapeutic platform.

Chemical modification of hyaluronic acid as a strategy for the development of advanced drug delivery systems

Hyaluronic acid (HA) has emerged as a promising biopolymer for various biomedical applications due to its biocompatibility, biodegradability, and intrinsic ability to interact with cell surface receptors, making it an attractive candidate for drug delivery systems and tissue engineering. Chemical modification of HA has opened up versatile possibilities to tailor its properties, enabling the development of advanced drug delivery systems and biomaterials with enhanced functionalities and targeted applications. This review analyzes the strategies and applications of chemically modified HA in the field of drug delivery and biomaterial development. The first part of the review focuses on the different methods and functional groups used for the chemical modification of HA, highlighting the impact of these modifications on its physicochemical properties, degradation behavior and interactions with drugs. The second part of the review evaluates the use of chemically modified HA in the development of advanced biomedical materials including nano- and microparticles, hydrogels and mucoadhesive materials with tailored drug release profiles, site-specific targeting and stimuli-responsive behavior. Thus, the review consolidates the current advances and future perspectives in the field of chemical modification of HA, underscoring its immense potential to drive the development of advanced drug delivery systems and biomaterials with diverse biomedical applications.

Near-infrared light-boosted antimicrobial activity of minocycline/hyaluronan/carbon nanohorn composite toward peri-implantitis treatments

Dental implant therapy is a reliable treatment for replacing missing teeth. However, as dental implants become more widely used, peri-implantitis increasingly has become a severe complication, making successful treatment more difficult. As a result, the development of effective drug delivery systems (DDSs) and treatments for peri-implantitis are urgently needed. Carbon nanohorns (CNHs) are carbon nanomaterials that have shown promise for use in DDSs and have photothermal effects. The present study exploited the unique properties of CNHs to develop a phototherapy employing a near-infrared (NIR) photoresponsive composite of minocycline, hyaluronan, and CNH (MC/HA/CNH) for peri-implantitis treatments. MC/HA/CNH demonstrated antibacterial effects that were potentiated by NIR-light irradiation, a property that was mediated by photothermal-mediated drug release from HA/CNH. These antibacterial effects persisted even following 48 h of dialysis, a promising indication for the clinical use of this material. We propose that the treatment of peri-implantitis using NIR and MC/HA/CNH, in combination with surgical procedures, might be employed to target relatively deep affected areas in a timely and efficacious manner. We envision that this innovative approach will pave the way for future developments in implant therapy.

pH-responsive self-assembled nanoparticles for tumor-targeted drug delivery

Recent advances in the field of drug delivery have opened new avenues for the development of novel nanodrug delivery systems (NDDS) in cancer therapy. Self-assembled nanoparticles (SANPs) based on tumour microenvironment have great advantages in improving antitumor effect, and pH-responsive SANPs prepared by the combination of pH-responsive nanomaterials and self-assembly technology can effectively improve the efficacy and reduce the systemic toxicity of antitumor drugs. In this review, we describe the characteristics of self-assembly and its driving force, the mechanism of pH-responsive NDDS, and the nanomaterials for pH-responsive SANPs type. A series of pH-responsive SANPs for tumour-targeted drug delivery are discussed, with an emphasis on the relation between structural features and theranostic performance.

A review on revolutionizing ophthalmic therapy: Unveiling the potential of chitosan, hyaluronic acid, cellulose, cyclodextrin, and poloxamer in eye disease treatments

Ocular disorders, encompassing both common ailments like dry eye syndrome and more severe situations for instance age-related macular degeneration, present significant challenges to effective treatment due to the intricate architecture and physiological barriers of the eye. Polysaccharides are emerging as potential solutions for drug delivery to the eyes due to their compatibility with living organisms, natural biodegradability, and adhesive properties. In this review, we explore not only the recent advancements in polysaccharide-based technologies and their transformative potential in treating ocular illnesses, offering renewed optimism for both patients and professionals but also anatomy of the eye and the significant obstacles hindering drug transportation, followed by an investigation into various drug administration methods and their ability to overcome ocular-specific challenges. Our focus lies on biological adhesive polymers, including chitosan, hyaluronic acid, cellulose, cyclodextrin, and poloxamer, known for their adhesive characteristics enhancing drug retention on ocular surfaces and increasing bioavailability. A detailed analysis of material designs used in ophthalmic formulations, such as gels, lenses, eye drops, nanofibers, microneedles, microspheres, and nanoparticles, their advantages and limitations, the potential of formulations in improving therapeutic outcomes for various eye conditions. Moreover, we underscore the discovery of novel polysaccharides and their potential uses in ocular drug delivery.

Mild preparation of hyaluronic acid/silk fibroin sponges by modified crosslinking method

The composites composed of hyaluronic acid (HA) and silk fibroin (SF) exhibit great potential in diverse biomedical applications. However, the utilization of commercial crosslinkers such as 1,4-butanediol diglycidyl ether (BDDE) for crosslinking HA typically necessitates harsh conditions involving strong alkaline, which greatly limits its potential applications. In this study, a mild modified approach was developed to fabricate HA/SF blend sponges crosslinked by BDDE without alkaline conditions. The blend solutions were cryo-concentrated to induce crosslinking reactions. The mechanism of freezing crosslinking was elucidated by investigating the effects of ice crystal growth and HA molecular weight on the degree of crosslinking. The results revealed that HA achieved efficient crosslinking when its molecular weight exceeds 1000 kDa and freezing temperatures ranged from -40 °C to -20 °C. After introducing SF, multiple crosslinks were formed between SF and HA chains, producing water-stable porous sponges. The SEM results demonstrated that the introduction of SF effectively enhanced the interconnectivity between macropores through creating subordinate holes onto the pores wall. Raising the SF content significantly enhanced compression strength, resistance to enzymatic degradation and cell viability of blend sponges. This study provides a novel strategy for designing bioactive HA/SF blend sponges as substitutes for tissue repair and wound dressing.

Co-assembly of cisplatin and dasatinib in hyaluronan nanogel to combat triple negative breast cancer with reduced side effects

Treatment for triple negative breast cancer (TNBC) remains a huge challenge due to the lack of targeted therapeutics and tumor heterogenicity. Cisplatin (Cis) have demonstrated favorable therapeutic response in TNBC and thus is used together with various kinase inhibitors to fight the heterogenicity of TNBC. The combination of Cis with SRC inhibitor dasatinib (DAS) has shown encouraging anti-TNBC efficacy although the additive toxicity was commonly observed. To overcome the severe side effects of this Cis involved therapy, here we co-encapsulated Cis and DAS into a self-assembled hyaluronan (HA) nanogel (designated as HA/Cis/DAS (HCD) nanogel) to afford the TNBC targeted delivery by using the 4T1 mouse model. The acquired HCD nanogel was around 181 nm in aqueous solution, demonstrating the pharmacological activities of both Cis and DAS. Taking advantages of HA's targeting capability towards CD44 that is overexpressed on many TNBC cells, the HCD could well maintain the anticancer efficacy of the Cis and DAS combination, significantly increase the maximum tolerated dose and relieve the renal toxicity in vivo. The current HCD nanogel provides a potent strategy to improve the therapeutic outcome of Cis and DAS combination and thus representing a new targeted treatment option for TNBC.

Advanced application of carbohydrate-based micro/nanoparticles for rheumatoid arthritis

Rheumatoid arthritis (RA) is a kind of synovitis and progressive joint destruction disease. Dysregulated immune cell activation, inflammatory cytokine overproduction, and subsequent reactive oxidative species (ROS) production contribute to the RA process. Carbohydrates, including cellulose, chitosan, alginate and dextran, are among the most abundant and important biomolecules in nature and are widely used in biomedicine. Carbohydrate-based micro/nanoparticles(M/NPs) as functional excipients have the ability to improve the bioavailability, solubility and stability of numerous drugs used in RA therapy. For on-demand therapy, smart reactive M/NPs have been developed to respond to a variety of chemical and physical stimuli, including light, temperature, enzymes, pH and ROS, alternating their physical and macroscopic properties, resulting in innovative new drug delivery systems. In particular, advanced products with targeted dextran or hyaluronic acid are exploiting multiple beneficial properties at the same time. In addition to those that respond, there are promising new derivatives in development with microenvironment and chronotherapy effects. In this review, we provide an overview of these recent developments and an outlook on how this class of agents will further shape the landscape of drug delivery for RA treatment.

Exploring the Progress of Hyaluronic Acid Hydrogels: Synthesis, Characteristics, and Wide-Ranging Applications

This comprehensive review delves into the world of hyaluronic acid (HA) hydrogels, exploring their creation, characteristics, research methodologies, and uses. HA hydrogels stand out among natural polysaccharides due to their distinct features. Their exceptional biocompatibility makes them a top choice for diverse biomedical purposes, with a great ability to coexist harmoniously with living cells and tissues. Furthermore, their biodegradability permits their gradual breakdown by bodily enzymes, enabling the creation of temporary frameworks for tissue engineering endeavors. Additionally, since HA is a vital component of the extracellular matrix (ECM) in numerous tissues, HA hydrogels can replicate the ECM's structure and functions. This mimicry is pivotal in tissue engineering applications by providing an ideal setting for cellular growth and maturation. Various cross-linking techniques like chemical, physical, enzymatic, and hybrid methods impact the mechanical strength, swelling capacity, and degradation speed of the hydrogels. Assessment tools such as rheological analysis, electron microscopy, spectroscopy, swelling tests, and degradation studies are employed to examine their attributes. HA-based hydrogels feature prominently in tissue engineering, drug distribution, wound recovery, ophthalmology, and cartilage mending. Crafting HA hydrogels enables the production of biomaterials with sought-after qualities, offering avenues for advancements in the realm of biomedicine.

Polymer-Based Drug Delivery Systems for Cancer Therapeutics

Chemotherapy together with surgery and/or radiotherapy are the most common therapeutic methods for treating cancer. However, the off-target effects of chemotherapy are known to produce side effects and dose-limiting toxicities. Novel delivery platforms based on natural and synthetic polymers with enhanced pharmacokinetic and therapeutic potential for the treatment of cancer have grown tremendously over the past 10 years. Polymers can facilitate selective targeting, enhance and prolong circulation, improve delivery, and provide the controlled release of cargos through various mechanisms, including physical adsorption, chemical conjugation, and/or internal loading. Notably, polymers that are biodegradable, biocompatible, and physicochemically stable are considered to be ideal delivery carriers. This biomimetic and bio-inspired system offers a bright future for effective drug delivery with the potential to overcome the obstacles encountered. This review focuses on the barriers that impact the success of chemotherapy drug delivery as well as the recent developments based on natural and synthetic polymers as platforms for improving drug delivery for treating cancer.

Mucoadhesive Thiolated Hyaluronic Acid/Pluronic F127 Nanogel Formation via Thiol-Maleimide Click Reaction for Intravesical Drug Delivery

The development of nanocarriers to prolong the residence time and enhance the permeability of chemotherapeutic drugs on bladder mucosa is important in the postsurgery treatment of superficial bladder cancers (BCs). Here, the mucoadhesive HA-SH/PF127 nanogels composed of a temperature-sensitive Pluronic F127 (PF127) core and thiolated hyaluronic acid (HA-SH) shell were prepared by the emulsification/solvent evaporation method. The nanogels were constructed through the thiol-maleimide click reaction in the HA-SH aqueous side of the oil-water interface and self-oxidized cross-linking thiols between HA-SH. The HA-SH/PF127 nanogels prepared at different thiol-to-maleimide group molar ratios, water-to-oil volume ratios, and cross-linking reaction times were characterized regarding hydrodynamic diameter (Dh) and zeta potential (ζ), and the optimal formulation was obtained. The excellent mucoadhesive properties of the HA-SH/PF127 nanogels were evaluated by using the mucin particle method. Doxorubicin (DOX) was encapsulated in the PF127 core of DOX@HA-SH/PF127 nanogels with a high loading efficiency (87.5%) and sustained release from the nanogels in artificial urine. Ex vivo studies on porcine bladder mucosa showed that the DOX@HA-SH/PF127 nanogels enhanced the penetration of the DOX into the bladder mucosa without disrupting the mucus structure or the bladder tissue. A significant dose-dependent cytotoxic effect of DOX@HA-SH/PF127 nanogels on both T24 and MB49 cells was observed. The present study demonstrates that the mucoadhesive HA-SH/PF127 nanogels are a promising intravesical drug delivery system for superficial BC therapy.

Yield stress analysis of cellulose nanocrystals (CNCs) in hyaluronic acid suspensions

Due to their biodegradability features, cellulose nanocrystals (CNCs) and hyaluronic acid (HA) have been simultaneously used in the matrix of hydrogels for biomedical applications, such as corneal transplantation, and skin regeneration. Although rheology of these hydrogels may provide useful information for their applications, little to no attention has been paid to rheological characterization. In this study, we analyzed the rheology of HA-CNC suspensions and more specifically their yielding behavior. Through different rheological experiments, known as stress ramp, shear rate ramp and amplitude sweep; it was observed that HA-CNC gels possessed two yield points. Reproducible magnitudes of yield stress were obtained by optimizing the experimental conditions. The rheo-optics characterizations confirmed that the first and second yield points could be attributed to the bond and cage breakage phenomena. Studying the effect of concentration, the second yield stress increased linearly by CNC concentration, whereas the first yield point manifested a power-law dependence on concentration (exponent of 0.5). This power-law relationship was further justified by the evolution of average distance between the CNC individual particles (d), calculated through SAXS analysis.

Hyaluronan-arginine enhanced and dynamic interaction emerges from distinctive molecular signature due to electrostatics and side-chain specificity

Hyaluronan is a natural carbohydrate polymer with a negative charge that fosters gel-like conditions crucial for its cellular functions and industrial applications. As a recognized ligand for proteins, understanding their mutual interactions provides solid ground to tune hyaluronan's gel properties using biocompatible peptides. This work employs NMR and molecular dynamics simulations to identify molecular motifs relevant to hyaluronan-peptide interactions using arginine, lysine, and glycine oligopeptides. Arginine-rich peptides exhibit the strongest binding to hyaluronan according to chemical shift perturbation measurements, followed distantly by the similarly charged lysine. This difference highlights the significance of electrostatics and the peculiarities of the guanidinium side chain in arginine, capable of non-polar interactions that further stabilize the binding. Additional nuclear Overhauser effect measurements do not show stable interaction partners, precluding strong and well-defined complexes. Finally, molecular simulations support our findings and show an extended but significant interaction region, especially for arginine, responsible for the observed enhanced binding, which can also promote cross-linking of hyaluronan polymers. Our findings pave the way for optimizing biocompatible peptides to alter hyaluronan gels' properties efficiently and also explain why hyaluronan-protein interaction typically involves positively charged arginine-rich regions also capable of forming hydrogen bonds and non-polar interactions.

A tumor-targeted and enzyme-responsive gold nanorod-based nanoplatform with facilitated endo-lysosomal escape for synergetic photothermal therapy and protein therapy

To tackle the obstacles related to tumor targeting and overcome the limitations of single treatment models, we have developed a nanoplatform that is both tumor-targeted and enzyme-responsive. This nanoplatform integrates photothermal gold nanorods (AuNRs) and protein drugs into a single system. This nanosystem, known as AuNRs@HA-mPEG-Deta-LA, was fabricated by modifying gold nanorods (AuNRs) with a polymeric ligand called hyaluronic acid-grafted-(mPEG/diethylenetriamine-conjugated-lipoic acid). The purpose of this fabrication was to load cytochrome c (CC) and utilize it for the synergetic protein-photothermal therapy of cancer. The resulting nanoplatform exhibited a high efficiency in loading proteins and demonstrated excellent stability in different biological environments. Additionally, CC-loaded AuNRs@HA-mPEG-Deta-LA not only enabled localized hyperthermia for photothermal therapy (PTT) with laser irradiation but also facilitated the release of CC under the action of hyaluronidase, an enzyme known to be overexpressed in tumor cells. The confocal imaging results demonstrated that the presence of a specific polymeric ligand on this nanoparticle enhances the internalization of CD44-positive cancer cells, accelerates endo/lysosomal escape, and facilitates the controlled release of CC within the cells. Furthermore, the results of the MTT assay also showed that AuNRs@HA-mPEG-Deta-LA as a protein nanocarrier demonstrated excellent biocompatibility. Importantly, this synergistic therapeutic strategy effectively induced apoptosis in A549 cancer cells by increasing the intracellular concentration of CC and utilizing the photothermal conversion of AuNRs, which was observed to be more effective compared to using only protein therapy or PTT. Therefore, this study showcased a nanoplatform based on AuNRs that has great potential for tumor-targeted protein delivery in combination with PTT in cancer treatment.

Hollow CuS nanoparticles equipped with hydroxyapatite/hyaluronic acid coating for NIR/pH dual-responsive drug delivery

The near-infrared (NIR)/pH dual-responsive nanoplatform shows great potential in remote photothermal therapy for tumor on account of the near-infrared window in biological tissue and the mild acidic environment in tumor cells. CuS nanoplatform has become a rising star in the field of photothermal agents due to its excellent NIR responsiveness and photostability. In this work, hollow CuS nanoparticles with high photothermal conversion efficiency (42.42 %) were synthesized through a novel surfactant micelle-assisted method. Then, CuS@hydroxyapatite (HAP)/hyaluronic acid (HA) nanoclusters with controllable drug release property were prepared by capping HAP and HA on the surface of CuS via electrostatic self-assembly approach. The hollow structure of CuS and the large specific surface area of HAP ensure an outstanding doxorubicin hydrochloride (DOX) loading efficiency of 99.2 % in CuS@HAP/HA nanoclusters. The introduction of HA effectively retards the initial burst release of DOX and ensures the excellent biocompatibility of nanoclusters. More importantly, CuS@HAP/HA displays distinct NIR/pH dual-responsive drug release properties owing to the excellent NIR responsiveness of hollow CuS and the gradual dissolution of HAP under acidic conditions. This work provides an environmentally benign method to prepare CuS-based nanoclusters with excellent NIR/pH responsive drug delivery properties, which has great potential in remote photothermal therapy.

Biomimetic mineralization by confined diffusion with viscous hyaluronan network: Assembly of hierarchical flower-like supraparticles

Biomolecules-mediated biomimetic mineralization has been extensively investigated and applied to fabricate nano-assemblies with unique hierarchical architectures and salient properties. The confined-source ion diffusion plays a key role in the biomineralization process, but little investigative efforts have focused on it. Here, we developed a simple method to mimic the in vivo condition by a confined diffusion method, and hydroxyapatite nanoflower assemblies (HNAs) with exquisite hierarchical architectures were obtained. The HNAs were assembled from needle-like hybrid nanocrystals of hydroxyapatite and hyaluronan. The results revealed that the strong interactions between ions and hyaluronan led to the nucleation of hydroxyapatite and the following aggregation. The combination of the external diffusion field and the internal multiple interactions induced the self-assembling processes. Additionally, HNAs with colloid stability and excellent biocompatibility were proved to be a promising cargo carrier for intranuclear delivery. This work presents a novel biomimetic mineralization strategy based on confined diffusion system for fabricating delicate hydroxyapatite, which offers a new perspective for the development of biomimetic strategies.

Hyaluronic acid-empowered nanotheranostics in breast and lung cancers therapy

Nanomedicine application in cancer therapy is an urgency because of inability of current biological therapies for complete removal of tumor cells. The development of smart and novel nanoplatforms for treatment of cancer can provide new insight in tumor suppression. Hyaluronic acid is a biopolymer that can be employed for synthesis of smart nanostructures capable of selective targeting CD44-overexpressing tumor cells. The breast and lung cancers are among the most malignant and common tumors in both females and males that environmental factors, lifestyle and genomic alterations are among the risk factors for their pathogenesis and development. Since etiology of breast and lung tumors is not certain and multiple factors participate in their development, preventative measures have not been completely successful and studies have focused on developing new treatment strategies for them. The aim of current review is to provide a comprehensive discussion about application of hyaluronic acid-based nanostructures for treatment of breast and lung cancers. The main reason of using hyaluronic acid-based nanoparticles is their ability in targeting breast and lung cancers in a selective way due to upregulation of CD44 receptor on their surface. Moreover, nanocarriers developed from hyaluronic acid or functionalized with hyaluronic acid have high biocompatibility and their safety is appreciated. The drugs and genes used for treatment of breast and lung cancers lack specific accumulation at cancer site and their cytotoxicity is low, but hyaluronic acid-based nanostructures provide their targeted delivery to tumor site and by increasing internalization of drugs and genes in breast and lung tumor cells, they improve their therapeutic index. Furthermore, hyaluronic acid-based nanostructures can be used for phototherapy-mediated breast and lung cancers ablation. The stimuli-responsive and smart kinds of hyaluronic acid-based nanostructures such as pH- and light-responsive can increase selective targeting of breast and lung cancers.

The role of hyaluronic acid in the design and functionalization of nanoparticles for the treatment of colorectal cancer

Despite advances in new approaches for colorectal cancer (CRC) therapy, intravenous chemotherapy remains one of the main treatment options; however, it has limitations associated with off-target toxicity, tumor cell resistance due to molecular complexity and CRC heterogeneity, which lead to tumor recurrence and metastasis. In oncology, nanoparticle-based strategies have been designed to avoid systemic toxicity and increase drug accumulation at tumor sites. Hyaluronic acid (HA) has obtained significant attention thanks to its ability to target nanoparticles (NPs) to CRC cells through binding to cluster-determinant-44 (CD44) and hyaluronan-mediated motility (RHAMM) receptors, along with its efficient biological properties of mucoadhesion. This review proposes to discuss the state of the art in HA-based nanoparticulate systems intended for localized treatment of CRC, highlighting the importance of the mucoadhesion and active targeting provided by this polymer. In addition, an overview of CRC will be provided, emphasizing the importance of CD44 and RHAMM receptors in this type of cancer and the current challenges related to this disease, and important concepts about the physicochemical and biological properties of HA will also be addressed. Finally, this review aims to contribute to the advancement of accuracy treatment of CRC by the design of new platforms based on by HA.

Application of hyaluronic acid-based nanoparticles for cancer combination therapy

Cancer is a significant public health problem in the world. The treatment methods include surgery, chemotherapy, phototherapy, and immunotherapy. Due to their respective limitations, the treatment effect is often unsatisfactory, laying hidden dangers for metastasis and recurrence. Since their exceptional biocompatibility and excellent targeting capabilities, hyaluronic acid-based biomaterials have generated great interest as drug delivery methods for tumor therapy. Moreover, modified HA can self-assemble into hydrogels or nanoparticles (NPs) for precise drug administration. This article summarizes the application of HA-based NPs in combination therapy. Ultimately, it is anticipated that this research will offer guidance for creating various HA-based NPs utilized in numerous cancer therapies.

Modification and crosslinking strategies for hyaluronic acid-based hydrogel biomaterials

Hyaluronic acid (HA) is an attractive extracellular matrix-derived polymer. The related HA-based hydrogels are emerging to be the hotspots in the cutting edge of biomaterials. The continuous sights concentrate on exploring modification methods and crosslinking strategies to promote the advancement of HA-based hydrogels with enhanced physical/chemical properties and enriched biological performance. Here, the advances on modification methods and crosslinking strategies for fabricating HA-based hydrogels with diverse capacities are summarized. Firstly, the modification reactions that occur on the active hydroxyl, carboxyl and N-acetyl groups of HA molecule are discussed. Next, the emphasis is put on various crosslinking strategies including physical crosslinking, covalent crosslinking and dynamic covalent crosslinking. Finally, we provide a general summary and give a critical viewpoint on the remaining challenges and the future development of HA-based hydrogels. It is hoped that this review can provide new proposals for the specific design of functional hydrogel biomaterials.

Polysaccharide-based tumor microenvironment-responsive drug delivery systems for cancer therapy

The biochemical indicators of tumor microenvironment (TME) that are different from normal tissues provide the possibility for constructing intelligent drug delivery systems (DDSs). Polysaccharides with good biocompatibility, biodegradability, and unique biological properties are ideal materials for constructing DDSs. Nanogels, micelles, organic-inorganic nanocomposites, hydrogels, and microneedles (MNs) are common polysaccharide-based DDSs. Polysaccharide-based DDSs enable precise control of drug delivery and release processes by incorporating TME-specific biochemical indicators. The classification and design strategies of polysaccharide-based TME-responsive DDSs are comprehensively reviewed. The advantages and challenges of current polysaccharide-based DDSs are summarized and the future directions of development are foreseen. The polysaccharide-based TME-responsive DDSs are expected to provide new strategies and solutions for cancer therapy and make important contributions to the realization of precision medicine.

Hyaluronic acid-based prodrug nanomedicines for enhanced tumor targeting and therapy: A review

Hyaluronic acid (HA) represents a natural polysaccharide which has attracted significant attention owing to its improved tumor targeting capacity, enzyme degradation capacity, and excellent biocompatibility. Its receptors, such as CD44, are overexpressed in diverse cancer cells and are closely related with tumor progress and metastasis. Accordingly, numerous researchers have designed various kinds of HA-based drug delivery platforms for CD44-mediated tumor targeting. Specifically, the HA-based nanoprodrugs possess distinct advantages such as good bioavailability, long circulation time, and controlled drug release and retention ability and have been extensively studied during the past years. In this review, the potential strategies and applications of HA-modified nanoprodrugs for drug molecule delivery in anti-tumor therapy are summarized.

Hyaluronic acid-based M1 macrophage targeting and environmental responsive drug releasing nanoparticle for enhanced treatment of rheumatoid arthritis

Herein, hyaluronic acid (HA) and β-cyclodextrin (β-CD) is used to form targeted drug delivery platform HCPC/DEX NPs with previously prepared carbon dots (CDs) as cross-linker, dexamethasone (DEX) is loaded for rheumatoid arthritis (RA) treatment. The drug loading capacity of β-CD and M1 macrophage targeting of HA were utilized for efficient delivery of DEX to the inflammatory joints. Because of the environmental responsive degradation of HA, DEX can be released in 24 h and inhibit the inflammatory response in M1 macrophages. The drug loading of NPs is 4.79 %. Cellular uptake evaluation confirmed that NPs can specifically target to M1 macrophages via HA ligands, the uptake of M1 macrophages is 3.7 times that of normal macrophages. In vivo experiments revealed that NPs can accumulate in RA joints to alleviate inflammation and accelerate cartilage healing, the accumulation can be observed in 24 h. The cartilage thickness increased to 0.45 mm after HCPC/DEX NPs treatment, indicating its good RA therapeutic effect. Importantly, this study was the first to utilize the potential acid and reactive oxygen species responsiveness of HA to release drug and prepare M1 macrophage targeting nanodrug for RA treatment, which provides a safe and effective RA therapeutic strategy.

Supramolecular Nanozyme System Based on Polydopamine and Polyoxometalate for Photothermal-Enhanced Multienzyme Cascade Catalytic Tumor Therapy

The advent of enzyme-facilitated cascade events in which endogenous substrates within the human body are used to generate reactive oxygen species (ROS) has spawned novel cancer treatment possibilities. In this study, a supramolecular cascade catalytic nanozyme system was successfully developed, exhibiting photothermal-enhanced multienzyme cascade catalytic and glutathione (GSH) depletion activities and ultimately triggering the apoptosis-ferroptosis synergistic tumor therapy. The nanozyme system was fabricated using β-cyclodextrin-functionalized polydopamine (PDA) as the substrate, which was then entangled with polyoxometalate (POM) via electrostatic forces and assembled with adamantane-grafted hyaluronic acid and glucose oxidase (GOx) via host-guest supramolecular interaction for tumor targeting and GOx loading. The catalytic function of GOx facilitates the conversion of glucose to H2O2 and gluconic acid. In turn, this process affirms the propitious generation of hydroxyl radical (•OH) through the POM-mediated cascade catalysis. Additionally, the POM species actively deplete the intracellular GSH pool, initiating a cascade catalytic tumor therapy. In addition, the PDA-POM-mediated photothermal hyperthermia boosted the cascade catalytic effect and increased ROS production. This confers considerable promise for photothermal therapy (PTT)/nanocatalytic cancer therapy on supramolecular nanozyme systems. The in vitro and in vivo antitumor efficacy studies demonstrated that the supramolecular cascade catalytic nanozyme system was effective at reducing tumor development while maintaining an acceptable level of biocompatibility. Henceforth, this study is to widen the scope of cascade catalytic nanoenzyme production using supramolecular techniques, as well as endeavor to delineate a prospective pathway for the application of PTT-enhanced nanocatalytic tumor therapy.

A multi-bioresponsive self-assembled nano drug delivery system based on hyaluronic acid and geraniol against liver cancer

Herein, a multi-bioresponsive self-assembled nano-drug delivery system (HSSG) was constructed by conjugating the anticancer drug Geraniol (GER) to hyaluronic acid (HA) via a disulfide bond. The HSSG NPs displayed a uniform spherical shape with an average diameter of ∼110 nm, maintained high stability, and realized controlled drug release in the tumor microenvironment (pH/glutathione/hyaluronidase). Results of fluorescence microscopy and flow cytometry verified that HSSG NPs were selectively uptaken by human hepatocellular carcinoma cell lines HepG2 and Huh7 via CD44 receptor-mediated internalization. Studies on H22 tumor-bearing mice demonstrate that HSSG NPs could effectively accumulate at the tumor site for a long period. In vitro and in vivo studies show that HSSG NPs significantly promoted the death of cancer cells while reducing the toxicity as compared to GER. Therefore, the HSSG NPs have great potential in the treatment of tumors.

Hyaluronic Acid Modified Metal Nanoparticles and Their Derived Substituents for Cancer Therapy: A Review

The use of metal nanoparticles (M-NPs) in cancer therapy has gained significant consideration owing to their exceptional physical and chemical features. However, due to the limitations, such as specificity and toxicity towards healthy cells, their application in clinical translations has been restricted. Hyaluronic acid (HA), a biocompatible and biodegradable polysaccharide, has been extensively used as a targeting moiety, due to its ability to selectively bind to the CD44 receptors overexpressed on cancer cells. The HA-modified M-NPs have demonstrated promising results in improving specificity and efficacy in cancer therapy. This review discusses the significance of nanotechnology, the state of cancers, and the functions of HA-modified M-NPs, and other substituents in cancer therapy applications. Additionally, the role of various types of selected noble and non-noble M-NPs used in cancer therapy are described, along with the mechanisms involved in cancer targeting. Additionally, the purpose of HA, its sources and production processes, as well as its chemical and biological properties are described. In-depth explanations are provided about the contemporary applications of HA-modified noble and non-noble M-NPs and other substituents in cancer therapy. Furthermore, potential obstacles in optimizing HA-modified M-NPs, in terms of clinical translations, are discussed, followed by a conclusion and future prospects.

Carbohydrate polymer-based bioadhesive formulations and their potentials for the treatment of ocular diseases: A review

Eyes are directly exposed to the outer environment and susceptible to infections, leading to various ocular disorders. Local medication is preferred to treat eye diseases due to its convenience and compliance. However, the rapid clearance of the local formulations highly limits the therapeutic efficacy. In the past decades, several carbohydrate bioadhesive polymers (CBPs), such as chitosan and hyaluronic acid, have been used in ophthalmology for sustained ocular drug delivery. These CBP-based delivery systems have improved the treatment of ocular diseases to a large extent but also caused some undesired effects. Herein, we aim to summarize the applications of some typical CBPs (including chitosan, hyaluronic acid, cellulose, cyclodextrin, alginate and pectin) in treating ocular diseases from the general view of ocular physiology, pathophysiology and drug delivery, and to provide a comprehensive understanding of the design of the CBP-based formulations for ocular use. The patents and clinical trials of CBPs for ocular management are also discussed. In addition, a discussion on the concerns of CBPs in clinical use and the possible solutions is presented.

Emerging biomaterials for tumor immunotherapy

BACKGROUND

The immune system interacts with cancer cells in various intricate ways that can protect the individual from overproliferation of cancer cells; however, these interactions can also lead to malignancy. There has been a dramatic increase in the application of cancer immunotherapy in the last decade. However, low immunogenicity, poor specificity, weak presentation efficiency, and off-target side effects still limit its widespread application. Fortunately, advanced biomaterials effectively contribute immunotherapy and play an important role in cancer treatment, making it a research hotspot in the biomedical field.

MAIN BODY

This review discusses immunotherapies and the development of related biomaterials for application in the field. The review first summarizes the various types of tumor immunotherapy applicable in clinical practice as well as their underlying mechanisms. Further, it focuses on the types of biomaterials applied in immunotherapy and related research on metal nanomaterials, silicon nanoparticles, carbon nanotubes, polymer nanoparticles, and cell membrane nanocarriers. Moreover, we introduce the preparation and processing technologies of these biomaterials (liposomes, microspheres, microneedles, and hydrogels) and summarize their mechanisms when applied to tumor immunotherapy. Finally, we discuss future advancements and shortcomings related to the application of biomaterials in tumor immunotherapy.

CONCLUSION

Research on biomaterial-based tumor immunotherapy is booming; however, several challenges remain to be overcome to transition from experimental research to clinical application. Biomaterials have been optimized continuously and nanotechnology has achieved continuous progression, ensuring the development of more efficient biomaterials, thereby providing a platform and opportunity for breakthroughs in tumor immunotherapy.

Enzyme/GSH/pH-responsive hyaluronic acid grafted porous silica nanocarriers bearing Ag2S QDs for fluorescence imaging and combined therapy

Hyaluronic acid (HA) is a naturally polysaccharide that has been used for drug delivery, but is limited by low drug loading capacity and drug leakage in circulation. To improve drug delivery efficient, HA modified porous silica (pSiO₂) nanocarriers were successfully prepared for drug delivery and combining therapy. pSiO₂ nanocarriers have stable porous structure and high loading capacity, and pSiO₂/HA nanocarriers would possess advantages of HA-based carriers and pSiO₂ nanoparticles. Herein, pSiO₂ nanocarriers were prepared by two-phase process, followed by embedding Ag₂S QDs in the pore walls of pSiO₂ carriers, which render the carriers photothermal effect. pSiO₂ nanocarriers have size of 30 nm, large channels, and high loading capacity (29.3 %). To graft HA, a sensitive linker with alkyl amine and disulfide bond was conjugated on the surface of Ag₂S/pSiO₂ nanocarriers by three-step reaction. After loading doxorubicin (DOX), HA was grafted via sensitive linker onto the surface of Ag₂S/pSiO₂ carriers via the formation of amide bonds to seal the loaded drugs. The interaction between HA and CD44 confers the carrier targeting ability to cancer cells. HA coating can be degraded by hyaluronidase resulting in the release of internal cargo. The Ag₂S/pSiO₂/HA nanocarriers performs responsive drug release and combining photothermal chemotherapy.

Photothermal Hydrogels for Promoting Infected Wound Healing

Photothermal therapies (PTT), with spatiotemporally controllable antibacterial capabilities without inducing resistance, have shown encouraging prospects in the field of infected wound treatments. As an important platform for PTT, photothermal hydrogels exhibit attractive advantages in the field of infected wound treatment due to their excellent biochemical properties and have been intensively explored in recent years. This review summarizes the progress of the photothermal hydrogels for promoting infected wound healing. Three major elements of photothermal hydrogels, i.e., photothermal materials, hydrogel matrix, and construction methods, are introduced. Furthermore, different strategies of photothermal hydrogels in the treatment of infected wounds are summarized. Finally, the challenges and prospects in the clinical treatment of photothermal hydrogels are discussed.

Mediation of synergistic chemotherapy and gene therapy via nanoparticles based on chitosan and ionic polysaccharides

Nanoparticles (NPs)-based on various ionic polysaccharides, including chitosan, hyaluronic acid, and alginate have been frequently summarized for controlled release applications, however, most of the published reviews, to our knowledge, focused on the delivery of a single therapeutic agent. A comprehensive summarization of the co-delivery of multiple therapeutic agents by the ionic polysaccharides-based NPs, especially on the optimization of the polysaccharide structure for overcoming various extracellular and intracellular barriers toward maximized synergistic effects, to our knowledge, has been rarely explored so far. For this purpose, the strategies used for overcoming various extracellular and intracellular barriers in vivo were introduced first to provide guidance for the rational design of ionic polysaccharides-based NPs with desired features, including long-term circulation, enhanced cellular internalization, controllable drug/gene release, endosomal escape and improved nucleus localization. Next, four preparation strategies were summarized including three physical methods of polyelectrolyte complexation, ionic crosslinking, and self-assembly and a chemical conjugation approach. The challenges and future trends of this rapidly developing field were finally discussed in the concluding remarks. The important guidelines on the rational design of ionic polysaccharides-based NPs for maximized synergistic efficiency drawn in this review will promote the future generation and clinical translation of polysaccharides-based NPs for cancer therapy.

Characterization of Hyaluronic Acid-Coated PLGA Nanoparticles by Surface-Enhanced Raman Spectroscopy

Nanoparticles (NPs) coated with hyaluronic acid (HA) seem to be increasingly promising for targeted therapy due to HA chemical versatility, which allows them to bind drugs of different natures, and their affinity with the transmembrane receptor CD-44, overexpressed in tumor cells. However, an essential aspect for clinical use of NPs is formulation stability over time. For these reasons, analytical techniques capable of characterizing their physico-chemical properties are needed. In this work, poly(lactide-co-glycolide) (PLGA) NPs with an average diameter of 100-150 nm, coated with a few 10 s of nm of HA, were synthesized. For stability characterization, two complementary investigative techniques were used: Dynamic Light Scattering (DLS) and Surface-Enhanced Raman Scattering (SERS) spectroscopy. The first technique provided information on size, polidispersity index, and zeta-potential, and the second provided a deeper insight on the NP surface chemicals, allowing distinguishing of HA-coated NPs from uncoated ones. Furthermore, in order to estimate formulation stability over time, NPs were measured and monitored for two weeks. SERS results showed a progressive decrease in the signal associated with HA, which, however, is not detectable by the DLS measurements.

Polyethyleneimine-Based Drug Delivery Systems for Cancer Theranostics

With the development of nanotechnology, various types of polymer-based drug delivery systems have been designed for biomedical applications. Polymer-based drug delivery systems with desirable biocompatibility can be efficiently delivered to tumor sites with passive or targeted effects and combined with other therapeutic and imaging agents for cancer theranostics. As an effective vehicle for drug and gene delivery, polyethyleneimine (PEI) has been extensively studied due to its rich surface amines and excellent water solubility. In this work, we summarize the surface modifications of PEI to enhance biocompatibility and functionalization. Additionally, the synthesis of PEI-based nanoparticles is discussed. We further review the applications of PEI-based drug delivery systems in cancer treatment, cancer imaging, and cancer theranostics. Finally, we thoroughly consider the outlook and challenges relating to PEI-based drug delivery systems.

Colloidal Polyelectrolyte Complexes from Hyaluronic Acid: Preparation and Biomedical Applications

Hyaluronic acid (HA) is a naturally occurring polysaccharide which has been extensively exploited in biomedical fields owing to its outstanding biocompatibility. Self-assembly of HA and polycations through electrostatic interactions can generate colloidal polyelectrolyte complexes (PECs), which can offer a wide range of applications while being relatively simple to prepare with rapid and "green" processes. The advantages of colloidal HA-based PECs stem from the combined benefits of nanomedicine, green chemistry, and the inherent properties of HA, namely high biocompatibility, biodegradability, and biological targeting capability. Accordingly, colloidal PECs from HA have received increasing attention in the recent years as high-performance materials for biomedical applications. Considering their potential, this review is aimed to provide a comprehensive understanding of colloidal PECs from HA in complex with polycations, from the most fundamental aspects of the preparation process to their various biomedical applications, notably as nanocarriers for delivering small molecule drugs, nucleic acids, peptides, proteins, and bioimaging agents or the construction of multifunctional platforms.