An injectable micelle-hydrogel hybrid for localized and prolonged drug delivery in the management of renal fibrosis

Targeted therapy of kidney disease with nanoparticle drug delivery materials

With the development of nanomedicine, nanomaterials have been widely used, offering specific drug delivery to target sites, minimal side effects, and significant therapeutic effects. The kidneys have filtration and reabsorption functions, with various potential target cell types and a complex structural environment, making the strategies for kidney function protection and recovery after injury complex. This also lays the foundation for the application of nanomedicine in kidney diseases. Currently, evidence in preclinical and clinical settings supports the feasibility of targeted therapy for kidney diseases using drug delivery based on nanomaterials. The prerequisite for nanomedicine in treating kidney diseases is the use of carriers with good biocompatibility, including nanoparticles, hydrogels, liposomes, micelles, dendrimer polymers, adenoviruses, lysozymes, and elastin-like polypeptides. These carriers have precise renal uptake, longer half-life, and targeted organ distribution, protecting and improving the efficacy of the drugs they carry. Additionally, attention should also be paid to the toxicity and solubility of the carriers. While the carriers mentioned above have been used in preclinical studies for targeted therapy of kidney diseases both in vivo and in vitro, extensive clinical trials are still needed to ensure the short-term and long-term effects of nano drugs in the human body. This review will discuss the advantages and limitations of nanoscale drug carrier materials in treating kidney diseases, provide a more comprehensive catalog of nanocarrier materials, and offer prospects for their drug-loading efficacy and clinical applications.

Zwitterion-Lubricated Hydrogel Microspheres Encapsulated with Metformin Ameliorate Age-Associated Osteoarthritis

Chondrocyte senescence and reduced lubrication play pivotal roles in the pathogenesis of age-related osteoarthritis (OA). In the present study, highly lubricated and drug-loaded hydrogel microspheres are designed and fabricated through the radical polymerization of sulfobetaine (SB)-modified hyaluronic acid methacrylate using microfluidic technology. The copolymer contains a large number of SB and carboxyl groups that can provide a high degree of lubrication through hydration and form electrostatic loading interactions with metformin (Met@SBHA), producing a high drug load for anti-chondrocyte senescence. Mechanical, tribological, and drug release analyses demonstrated enhanced lubricative properties and prolonged drug dissemination of the Met@SBHA microspheres. RNA sequencing (RNA-seq) analysis, network pharmacology, and in vitro assays revealed the extraordinary capacity of Met@SBHA to combat chondrocyte senescence. Additionally, inducible nitric oxide synthase (iNOS) has been identified as a promising protein modulated by Met in senescent chondrocytes, thereby exerting a significant influence on the iNOS/ONOO-/P53 pathway. Notably, the intra-articular administration of Met@SBHA in aged mice ameliorated cartilage senescence and OA pathogenesis. Based on the findings of this study, Met@SBHA emerges as an innovative and promising strategy in tackling age-related OA serving the dual function of enhancing joint lubrication and mitigating cartilage senescence.

Systemic platelet inhibition with localized chemotherapy by an injectable ROS-scavenging gel against postsurgical breast cancer recurrence and metastasis

Early solid tumors benefit from surgical resection, but residual stubborn microtumors, pro-inflammatory microenvironment and activated platelets at the postoperative wound site are prone to recurrence and metastasis, resulting in poor prognosis. Here, we developed a dual-pronged strategy consisting of (i) in-situ forming ROS-scavenging gels loaded with anticancer drugs at the postoperative wound site to improve the tumor microenvironment and inhibit the recurrence of residual microtumors after orthotopic surgery, and (ii) systemic administration of clopidegrol via albumin nanoparticles for inhibiting activated platelets in the circulation thus inhibiting tumor remote migration. In a mouse model of postoperative recurrence and metastasis of orthotopic 4T1 breast cancer, the dual-pronged strategy greatly inhibited postoperative orthotopic tumor recurrence and reduced lung metastasis. This work provides an effective strategy for the postoperative intervention and treatment of solid tumors to inhibit postoperative tumor recurrence and metastasis, which has the potential to improve the prognosis and survival of patients with postoperative solid tumors. STATEMENT OF SIGNIFICANCE: Early-stage solid tumors benefit from surgical resection. However, the presence of residual microtumors, pro-inflammatory tumor microenvironment, and activated platelets at the postoperative wound site lead to recurrence and metastasis, ultimately resulting in poor prognosis. Here, we have devised a dual-pronged approach that includes (i) in-situ forming ROS-scavenging gels loaded with anticancer drugs (TM@Gel) at the wound site after surgery to enhance the tumor microenvironment (TME) and hinder the reappearance of residual microtumors, and (ii) systemic administration of clopidegrol through albumin nanoparticles (HHP) for inhibiting activated platelets in the circulation thus impeding tumor distant migration. This work provides a viable option for postoperative intervention and treatment of solid tumors to suppress postoperative tumor recurrence and metastasis.

Hemicellulose-based nanoaggregate-incorporated biocompatible hydrogels with enhanced mechanical properties and sustained controlled curcumin release behaviors

Local drug delivery has generated considerable interest due to its controlled and sustained drug release at the target site on demand. Nanoaggregate-incorporated composite hydrogels are desirable as local drug delivery systems; however, it is difficult to achieve sustained and controlled hydrophobic drug release and superior mechanical properties in one system. Herein, a "smart" composite hydrogel was synthesized by incorporating hemicellulose-based nanoaggregates into a double network consisting of alginate/Ca2+ and polyacrylic acid-co-dimethylaminoethyl methacrylate [P(AA-co-DMAEMA)]. Hemicellulose-based nanoaggregates were assembled from xylan-rich hemicellulose laurate methacrylate (XH-LA-MA) polymers and entrapped into the hydrogel framework via chemical fixation. Another composite hydrogel with physically embedded hemicellulose laurate (XH-LA) nanoaggregates was prepared as a comparison. Accordingly, covalently cross-linked XH-LA-MA nanoaggregates in hydrogels resulted in a denser pore structure and reinforced mechanical properties. Nanoaggregate diffusion analysis revealed that covalent bonding between the nanoaggregates and the hydrogel framework contributed to prolonged diffusion behavior. Curcumin (Cur)-loaded XH-LA-MA composite hydrogels enabled sustained Cur release in simulated body fluid and showed stimulus responsiveness toward ethylenediaminetetraacetic acid (EDTA) and/or glutathione (GSH). All the composite hydrogels were biocompatible, as verified by Cell Counting Kit-8 (CCK-8) assay against NIH/3T3 cells. These composite hydrogels hold great potential as a promising dosage form for biomedical applications.

The occurrence and development mechanisms of esophageal stricture: state of the art review

BACKGROUND

Esophageal strictures significantly impair patient quality of life and present a therapeutic challenge, particularly due to the high recurrence post-ESD/EMR. Current treatments manage symptoms rather than addressing the disease's etiology. This review concentrates on the mechanisms of esophageal stricture formation and recurrence, seeking to highlight areas for potential therapeutic intervention.

METHODS

A literature search was conducted through PUBMED using search terms: esophageal stricture, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles.

RESULTS

Preclinical studies and data from animal studies suggest that the mechanisms that may lead to esophageal stricture include overdifferentiation of fibroblasts, inflammatory response that is not healed in time, impaired epithelial barrier function, and multimethod factors leading to it. Dysfunction of the epithelial barrier may be the initiating mechanism for esophageal stricture. Achieving perfect in-epithelialization by tissue-engineered fabrication of cell patches has been shown to be effective in the treatment and prevention of esophageal strictures.

CONCLUSION

The development of esophageal stricture involves three stages: structural damage to the esophageal epithelial barrier (EEB), chronic inflammation, and severe fibrosis, in which dysfunction or damage to the EEB is the initiating mechanism leading to esophageal stricture. Re-epithelialization is essential for the treatment and prevention of esophageal stricture. This information will help clinicians or scientists to develop effective techniques to treat esophageal stricture in the future.

Roadmap on multifunctional materials for drug delivery

This Roadmap on drug delivery aims to cover some of the most recent advances in the field of materials for drug delivery systems (DDSs) and emphasizes the role that multifunctional materials play in advancing the performance of modern DDSs in the context of the most current challenges presented. The Roadmap is comprised of multiple sections, each of which introduces the status of the field, the current and future challenges faced, and a perspective of the required advances necessary for biomaterial science to tackle these challenges. It is our hope that this collective vision will contribute to the initiation of conversation and collaboration across all areas of multifunctional materials for DDSs. We stress that this article is not meant to be a fully comprehensive review but rather an up-to-date snapshot of different areas of research, with a minimal number of references that focus upon the very latest research developments.

Multifunctional Hydrogel Eye Drops for Synergistic Treatment of Ocular Inflammatory Disease

Uveitis is a complex ocular inflammatory disease with a multifactorial etiology that can result in blindness. Although corticosteroid eye drops are the primary treatment for anterior uveitis, their efficacy is limited by low bioavailability, adverse effects, and a narrow focus on inflammation. In this study, the multifunctional hydrogel eye drops (designated as DCFH) were developed by incorporating the anti-inflammatory agent dexamethasone (DSP) and reactive oxygen species (ROS) scavenger cerium-based metal-organic frameworks (Ce-MOFs) into thermosensitive triblock copolymer F127 for the synergistic treatment against uveitis. The resulting F127 eye drops offer a favorable alternative to ophthalmic solution due to its thermosensitivity, thixotropy, light transmittance, improved ocular bioavailability, and unexpected anti-inflammatory efficacy. Notably, the participation of nanoporous Ce-MOFs, functional drug carriers, not only reduces ROS level but also boosts the anti-inflammatory activity of DSP in vitro. Therapeutically, the multifunctional DCFH exhibits superior efficacy in treating endotoxin-induced uveitis by mitigating the ophthalmic inflammatory reaction, suppressing inflammatory cytokines (e.g., TNF-α, IL-6, and IL-17) and downregulating the expression of iNOS and NLPR3. This synergistic treatment provides a valuable and promising approach for the management of uveitis and other ocular inflammatory conditions.

Targeted Delivery of Celastrol via Chondroitin Sulfate Derived Hybrid Micelles for Alleviating Symptoms in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is caused by an accumulation of excess fat in the liver leading to oxidative stress and liver cell injury, as well as overproduction of inflammatory cytokines. CD44 has been identified as a potential therapeutic target in the development of NAFLD to nonalcoholic steatohepatitis. Here, chondroitin sulfate (CS) is selected to construct a CD44-targeted delivery system for the treatment of NAFLD. Specifically, two CS-derived amphiphilic materials including CS conjugated with either 4-aminophenylboronic acid pinacol ester (CS-PBE) or phenformin (CS-PFM) were synthesized, respectively. The presence of PBE moieties on CS-PBE rendered the vehicle with enhanced loading capacity and scavenging potential against reactive oxygen species, while the presence of guanidine moieties on CS-PFM enhanced the internalization of vehicles in the differentiated hepatocytes. Next, celastrol (CLT) was encapsulated in the hybrid micelle to afford CS-Hybrid/CLT, which demonstrates sufficient stability, enhanced cellular uptake efficiencies in differentiated HepG2 cells, and therapeutic potential to alleviate lipid accumulation in differentiated HepG2 cells. In a high-fat-diet-induced NAFLD rat model, CS-Hybrid/CLT micelles demonstrated the capacity to dramatically decrease hepatic lipid accumulation and free fatty acid levels with greatly improved pathologic liver histology and downregulated hepatic inflammation levels. These results suggest that CS-based amphiphilic micelles may offer a promising strategy to effectively deliver therapeutic cargos to the liver for the treatment of NAFLD.

Effect of Albumin Corona Conformation on In Vitro and In Vivo Profiles of Intravenously Administered Nanoparticles

Under physiological conditions, nanoparticles (NPs) inevitably interact with proteins, resulting in extensive protein adsorption and the formation of a protein corona. Recent studies have shown that the different surface properties of NPs lead to varying degrees of conformational changes of adsorbed proteins. However, the impact of corona protein conformation on the in vitro and in vivo profiles of NPs remain largely unexplored. Herein, d-α-tocopherol polyethylene glycol 1000 succinate-based NPs with natural human serum albumin (HSA_N) corona or thermally denatured HSA (HSA_D) corona were synthesized following a previously established method. We then conducted a systematic study of the protein conformation as well as adsorption behaviors. Additionally, the impact of protein corona conformation on the NPs profiles in vitro and in vivo were elucidated to gain insight into its biological behaviors as a targeted delivery system for renal tubule diseases. Overall, NPs modified by HSA_N corona showed improved serum stability, greater cell uptake efficiency, better renal tubular targetability, and therapeutic efficacy on acute kidney injury in rats than NPs modified by HSA_D corona. Hence, the conformation of protein adsorbed on the surface of NPs may impact the in vitro and in vivo profiles of NPs.

Advanced Drug Delivery Systems for Renal Disorders

Kidney disease management and treatment are currently causing a substantial global burden. The kidneys are the most important organs in the human urinary system, selectively filtering blood and metabolic waste into urine via the renal glomerulus. Based on charge and/or molecule size, the glomerular filtration apparatus acts as a barrier to therapeutic substances. Therefore, drug distribution to the kidneys is challenging, resulting in therapy failure in a variety of renal illnesses. Hence, different approaches to improve drug delivery across the glomerulus filtration barrier are being investigated. Nanotechnology in medicine has the potential to have a significant impact on human health, from illness prevention to diagnosis and treatment. Nanomaterials with various physicochemical properties, including size, charge, surface and shape, with unique biological attributes, such as low cytotoxicity, high cellular internalization and controllable biodistribution and pharmacokinetics, have demonstrated promising potential in renal therapy. Different types of nanosystems have been employed to deliver drugs to the kidneys. This review highlights the features of the nanomaterials, including the nanoparticles and corresponding hydrogels, in overcoming various barriers of drug delivery to the kidneys. The most common delivery sites and strategies of kidney-targeted drug delivery systems are also discussed.

Ultrathin, elastic, and self-adhesive nanofiber bio-tape: An intraoperative drug-loading module for ureteral stents with localized and controlled drug delivery properties for customized therapy

During the postoperative management of urinary diseases, oral or intravenous administration of drugs and implanting ureteral stents are usually required, making localized drug delivery by ureteral stent a precise and effective medication strategy. In the traditional drug loading method, the drug was premixed in the implants in production lines and the versatility of drugs was restricted. However, the complex situation in the urinary system fails the possibility of finding a “one fits all” medication plan, and the intraoperative drug-loading of implants is highly desired to support customized therapy. Here, we designed an ultrathin (8 μm), elastic, and self-adhesive nanofiber bio-tape (NFBT) that can easily encapsulate drugs on the stent surface for controllable localized drug delivery. The NFBT exhibited high binding strength to a ureteral stent, a sustained release over 7 d in PBS for hydrophilic drug, and a zero-order release curve over 28 days for the hydrophobic drug nitrofurantoin (NFT). Further in vivo experiments using a porcine ureteral tract infection model demonstrated that NFBT loaded with NFT could significantly reduce the bacterial concentration in urine. The total amount of NFT delivered by the NFBT was about 2.68 wt% of the recommended dose for the systemic administration.

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An intra operation drug-loading strategy and drug carrier for personalized post-operation management of urinary disease.

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The NFBT is ultrathin (∼8 μm) with enough binding stress to resist displacement bought by ureteral peristalsis.

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In vivo antibacterial rate >99.9% for 28 d (porcine UTI model), with 2.68 wt% of the systemically administration dosage.

Enhanced bioavailability and pharmacokinetics of a novel hybrid-hydrogel formulation of fisetin orally administered in healthy individuals: a randomised double-blinded comparative crossover study

Fisetin, a polyphenol found in several fruits and vegetables, has shown potential health benefits in many pre-clinical studies for neuroprotection, cardioprotection, chemoprevention, diabetes, inflammation and oxidative stress. However, the clinical effectiveness of fisetin may be limited by its poor bioavailability when ingested. Using a novel green technology of Hybrid-FENUMAT™, a food-grade fisetin formulation (FF-20) was developed through encapsulation of fisetin micelles into fenugreek galactomannan (FG) hydrogel scaffold to improve its physical characteristics and bioavailability. This is the first human pharmacokinetic study of fisetin following a single-dose, comparative, double-blinded, cross-over protocol, supplementing with FF-20 and unformulated fisetin (UF). Fifteen healthy volunteers were given a single dose of 1000 mg UF or 1000 mg FF-20 (delivering 192 mg fisetin) with a 10-d washout period between each dose. Blood samples were taken at 0⋅5, 1, 2, 3, 5, 8 and 12 h after both days of supplementation to quantify fisetin and geraldol, an active metabolite. The plasma concentration of fisetin when individuals consumed FF-20 was 26⋅9-fold greater than UF as determined by the area under the curve over 12 h [AUC0–12 h (FF-20) = 341⋅4 v . AUC0–12 h (UF) = 12⋅67]. The maximum plasma concentration (C max) was also more than twenty-three times higher when supplemented with FF-20 (238⋅2 ng/ml) compared to UF (9⋅97 ng/ml). The encapsulation also reduced the amount of conversion of fisetin to geraldol. No adverse events were reported during the study. Therefore, the encapsulation of fisetin into FG dietary fibre hydrogel scaffold could improve its delivery and bioavailability in human subjects.

Injectable light-assisted thermo-responsive methylcellulose-sodium humate hydrogel proposed for photothermal ablation and localized delivery of cisplatin

This study aimed to develop injectable light-assisted thermo-responsive methylcellulose hydrogels filled with sodium humate, which were proposed for photothermal ablation and localized cisplatin delivery. Sodium humate converts light energy from laser beams into thermal energy, which causes methylcellulose to gel, thereby controlling the release of chemotherapy agents. Meanwhile, light emission causes to the photothermal ablation of tumor cells. For determining the optimal production conditions, different concentrations of sodium humate and light emission times were investigated. Results show that hydrogel uniformity is highly dependent on variables. An increase in sodium humate concentration and emission time resulted in a slight reduction in swelling ratio and an increase in durability. According to the simulation conditions, the cisplatin release profile was consistent with a non-Fickian mechanism with a predominant erosion contribution. In conjugation with increasing light emission time and sodium humate content, the storage modulus and viscosity increased, demonstrating hydrogel’s sol-gel transition and long-lasting durability. The intrinsic fluorescence spectroscopy study revealed that the hydrogel-model protein complex empowered hydrogel bio-performance. Laser emission and cisplatin release synergistically reduced the number of viable osteosarcoma cell lines, suggesting the possibility of tumor ablation. This study describes the potential of simultaneous photothermal therapy and chemotherapy in osteosarcoma treatment, laying the groundwork for future preclinical and clinical trials.

Renal Artery Catheterization for Microcapsules' Targeted Delivery to the Mouse Kidney

The problem of reducing the side effects associated with drug distribution throughout the body in the treatment of various kidney diseases can be solved by effective targeted drug delivery. The method described herein involves injection of a drug encapsulated in polyelectrolyte capsules to achieve prolonged local release and long-term capillary retention of several hours while these capsules are administered via the renal artery. The proposed method does not imply disruption (puncture) of the renal artery or aorta and is suitable for long-term chronic experiments on mice. In this study, we compared how capsule size and dosage affect the target kidney blood flow. It has been established that an increase in the diameter of microcapsules by 29% (from 3.1 to 4.0 μm) requires a decrease in their concentration by at least 50% with the same suspension volume. The photoacoustic method, along with laser speckle contrast imaging, was shown to be useful for monitoring blood flow and selecting a safe dose. Capsules contribute to a longer retention of a macromolecular substance in the target kidney compared to its free form due to mechanical retention in capillaries and slow impregnation into surrounding tissues during the first 1-3 h, which was shown by fluorescence tomography and microscopy. At the same time, the ability of capillaries to perform almost complete "self-cleaning" from capsular shells during the first 12 h leads to the preservation of organ tissues in a normal state. The proposed strategy, which combines endovascular surgery and the injection of polymer microcapsules containing the active substance, can be successfully used to treat a wide range of nephropathies.

Co-Delivery of Dexamethasone and Captopril by α8 Integrin Antibodies Modified Liposome-PLGA Nanoparticle Hybrids for Targeted Anti-Inflammatory/Anti-Fibrosis Therapy of Glomerulonephritis

Purpose

Mesangial cells-mediated glomerulonephritis refers to a category of immunologically mediated glomerular injuries characterized by infiltration of circulating inflammatory cells, proliferation of mesangial cells, and the common pathological manifestation to the later stage is renal fibrosis, accompanied by excessive accumulation of extracellular matrix (ECM). Treatment regimens include glucocorticoids and immunosuppressive agents, but their off-target distribution causes severe systemic toxicity. Hence, specific co-delivery of “anti-inflammatory/anti-fibrosis” drugs to the glomerular mesangial cell (MC) region is expected to produce better therapeutic effects.

Methods

A novel kidney-targeted nanocarrier drug delivery system targeting MCs was constructed using passive targeting resulting from the difference in pore size between the glomerular endothelial layer and the basement membrane, and active targeting based on the specific binding of antibodies and antigens. Specifically, a liposome-nanoparticle hybrid (PLGA-LNHy) was formed by coating the surface of PLGA nanoparticles (NPs) with a phospholipid bilayer, and then PLGA-LNHy was co-modified with PEG and α8 integrin antibodies to obtain PLGA immunoliposomes (PLGA-ILs).

Results

The results showed that the obtained NPs had a core-shell structure, uniform and suitable particle size (119.1 ± 2.31 nm), low cytotoxicity, and good mesangial cell-entry ability, which can successfully accumulate in the glomerular MC region. Both dexamethasone (DXMS) and captopril (CAP) were loaded onto PLGA-ILs with a drug loading of 10.22 ± 1.00% for DXMS and 6.37 ± 0.25% for CAP (DXMS/CAP@PLGA-ILs). In vivo pharmacodynamics showed that DXMS/CAP@PLGA-ILs can effectively improve the pathological changes in the mesangial area and positive expression of proliferating cell nuclear antigen (PCNA) in glomeruli as well as reduce the expression of inflammatory factors, fibrotic factors and reactive oxygen species (ROS). Thus, renal inflammation and fibrosis were relieved.

Conclusion

We have provided a strategy to increase nanoparticle accumulation in MCs with the potential to implement regulatory effects of anti-inflammatory and anti-fibrosis in glomerulonephritis (GN).

In situ gel implant for postsurgical wound management and extended chemoimmunotherapy against breast cancer recurrence

Postsurgical recurrence of breast cancer is closely related to the inflammatory tumor microenvironment evoked by surgical wounds. Toll-like receptor 4 (TLR4) signaling contributes to NF-κB activation thus secreting various inflammatory cytokines. Herein, we developed an in situ photo-crosslinked hydrogel (D/T gel) concurrently loaded with doxorubicin (DOX) and a TLR4 antagonist, resatorvid (TAK-242). Its therapeutic effect against breast cancer postsurgical relapse was accomplished through remodeling the proinflammatory tumor microenvironment. The obtained gel network exhibited ideal biodegradability and biocompatibility, which motivated dermal wound healing in the full thickness wound model in mice. Despite the initial burst release of DOX, D/T gels exhibited extended-release of both DOX and TAK-242 for up to 21 days in vitro. TAK-242 was demonstrated to inhibit the lipopolysaccharide-induced NF-κB activation and downregulate TLR4 levels in both RAW264.7 and 4T1 cells. In a 4T1-Luc tumor postsurgical recurrence model, D/T gel significantly suppressed recurrent tumor growth by elevating the concentrations of DOX and TAK-242 at the tumor sites and remodeling the TLR4 activation-induced proinflammatory microenvironment. Overall, the D/T gel platform technology is proven to deliver therapeutics directly to the surgical wound bed, attenuating the dual inflammatory responses induced by DOX and surgical wounding thus greatly potentiating its efficacy in preventing postsurgical tumor recurrence. STATEMENT OF SIGNIFICANCE: Postsurgical recurrence of breast cancer is closely related to the inflammatory tumor microenvironment (TME) evoked by surgical wounds. Although chemotherapeutics lead to extensive residual tumor cell necrosis, multiple inflammatory cytokines are secreted simultaneously, which are conducive to tumor recurrence. In this work, a TLR4 antagonist, TAK-242, was combined with DOX to reverse the dual inflammatory TME induced by surgical wounding and chemotherapy. To elevate the concentration of therapeutics at the tumor site, a photocrosslinked hydrogel (D/T gel) implant coloaded with TAK-242 and DOX was developed and applied on the postsurgical bed. Consequently, D/T gel attenuated the dual inflammatory responses and greatly potentiated its efficacy in preventing postsurgical tumor recurrence.

Ultrashort Peptides and Hyaluronic Acid-Based Injectable Composite Hydrogels for Sustained Drug Release and Chronic Diabetic Wound Healing

Peptide hydrogels are widely used for biomedical applications owing to their good biocompatibility and unique advantages in terms of amino acid-based structures and functions. However, the exploration of the peptide/saccharide composite hydrogels as potential biomaterials for chronic diabetic wound healing is still limited. Herein, hyaluronic acid (HA) was incorporated into diphenylalanine (FF) conjugated with different aromatic moieties by a one-pot reaction. Our results showed that the dipeptide derivatives modified by benzene (B), naphthalene (N), and pyrene (P) self-assembled into composite hydrogels with uniform distribution and good mechanical properties in the presence of HA. The obtained N-FF/HA composite hydrogel exhibited greatly improved self-healing properties via injection syringe needle operation and good biocompatibility on human skin fibroblast (HSF) cells. Besides, the structure of thinner nanofibers and honeycomb networks inside the composite hydrogel allowed for a longer sustained release of curcumin, a hydrophobic drug for anti-inflammation and wound healing. The curcumin-loaded N-FF/HA composite hydrogels could promote chronic wound healing in the streptozotocin-induced type I diabetic mouse model. The results suggested that our developed saccharide-peptide hydrogels could serve as very promising synthetic biomaterials for applications in both drug delivery and wound healing in the future.

Antitumoral Activities of Curcumin and Recent Advances to ImProve Its Oral Bioavailability

Curcumin, a main bioactive component of the Curcuma longa L. rhizome, is a phenolic compound that exerts a wide range of beneficial effects, acting as an antimicrobial, antioxidant, anti-inflammatory and anticancer agent. This review summarizes recent data on curcumin's ability to interfere with the multiple cell signaling pathways involved in cell cycle regulation, apoptosis and the migration of several cancer cell types. However, although curcumin displays anticancer potential, its clinical application is limited by its low absorption, rapid metabolism and poor bioavailability. To overcome these limitations, several curcumin-based derivatives/analogues and different drug delivery approaches have been developed. Here, we also report the anticancer mechanisms and pharmacokinetic characteristics of some derivatives/analogues and the delivery systems used. These strategies, although encouraging, require additional in vivo studies to support curcumin clinical applications.

Injectable Micelle-Incorporated Hydrogels for the Localized Chemo-Immunotherapy of Breast Tumors

Although immune checkpoint blockade (ICB) holds potential for the treatment of various tumors, a considerable proportion of patients show a limited response to ICB therapy due to the low immunogenicity of a variety of tumors. It has been shown that some chemotherapeutics can turn low-immunogenic tumors into immunogenic phenotypes by inducing a cascade of immune responses. In this paper, we synthesized an injectable micelle-incorporated hydrogel, which was able to sequentially release the chemotherapeutic gemcitabine (GEM) and the hydrophobic indoleamine 2, 3-dioxygenase inhibitor, d-1-methyltryptophan (d-1MT) at tumor sites. The hydrogel was formed via the thiol-ene click reaction between the thiolated chondroitin sulfate and the micelle formed by amphiphilic methacrylated Pluronic F127, in which hydrophobic d-1MT was encapsulated in the core of the F127 micelles and the hydrophilic GEM was dispersed in the hydrogel network. The successive release of chemotherapeutics and immune checkpoint inhibitors at tumor tissues will first promote the infiltration of cytotoxic T lymphocytes and subsequently induce a robust antitumor immune response, ultimately exerting a synergetic therapeutic efficacy. In a 4T1 tumor-bearing mice model, our results showed that the combination of chemotherapy and immunotherapy through the micelle-incorporated hydrogel triggered an effective antitumor immune response and inhibited tumor metastasis to the lung. Our results highlight the potential of the injectable micelle-incorporated hydrogel for the localized chemo-immunotherapy in the treatment of breast tumors.

Therapeutic and delivery strategies of phytoconstituents for renal fibrosis

Chronic kidney disease (CKD) is one of the most common diseases endangering human health and life. By 2030, 14 per 100,000 people may die from CKD. Renal fibrosis (RF) is an important intermediate link and the final pathological change during CKD progression to the terminal stage. Therefore, identifying safe and effective treatment methods for RF has become an important goal. In 2018, the World Health Organization introduced traditional Chinese medicine into its effective global medical program. Various phytoconstituents that affect the RF process have been extracted from different plants. Here, we review the potential therapeutic capabilities of active phytoconstituents in RF treatment and discuss how phytoconstituents can be structurally modified or combined with other ingredients to enhance efficiency and reduce toxicity. We also summarize phytoconstituent delivery strategies to overcome renal barriers and improve bioavailability and targeting.

Extended-release of therapeutic microRNA via a host-guest supramolecular hydrogel to locally alleviate renal interstitial fibrosis

Activated fibroblasts are critical contributors to renal interstitial fibrosis thus becoming the cellular target for fibrosis treatment. Previously, microRNA 29 b (miR-29 b) is shown to be down-regulated in various animal models of renal fibrosis. Herein, we describe a facile strategy to achieve localized and sustained delivery of therapeutic microRNA to the kidney via a host-guest supramolecular hydrogel. Specifically, cationic bovine serum albumin is used to complex with miR-29 b to afford nanocomplexes (cBSA/miR-29 b), which is proven to specifically inhibit fibroblast activation in a dose-dependent manner in vitro. Following unilateral ureteral obstruction in mice, a single injection of the hydrogel loaded with cBSA/miR-29 b in vivo, significantly down-regulated proteins and genes related to fibrosis for up to 21 days without affecting the normal liver or kidney functions. Overall, the localized delivery of cBSA/miR-29 b via a host-guest supramolecular hydrogel represents a safe and effective intervention strategy to delay and reverse the progression of interstitial renal fibrosis.

Label-Free Fluorescence Molecular Beacon Probes Based on G-Triplex DNA and Thioflavin T for Protein Detection

Protein detection plays an important role in biological and biomedical sciences. The immunoassay based on fluorescence labeling has good specificity but a high labeling cost. Herein, on the basis of G-triplex molecular beacon (G3MB) and thioflavin T (ThT), we developed a simple and label-free biosensor for protein detection. The biotin and streptavidin were used as model enzymes. In the presence of target streptavidin (SA), the streptavidin hybridized with G3MB-b (biotin-linked-G-triplex molecular beacon) perfectly and formed larger steric hindrance, which hindered the hydrolysis of probes by exonuclease III (Exo III). In the absence of target streptavidin, the exonuclease III successively cleaved the stem of G3MB-b and released the G-rich sequences which self-assembled into a G-triplex and subsequently activated the fluorescence signal of thioflavin T. Compared with the traditional G-quadruplex molecular beacon (G4MB), the G3MB only needed a lower dosage of exonuclease III and a shorter reaction time to reach the optimal detection performance, because the concise sequence of G-triplex was good for the molecular beacon design. Moreover, fluorescence experiment results exhibited that the G3MB-b had good sensitivity and specificity for streptavidin detection. The developed label-free biosensor provides a valuable and general platform for protein detection.