Injectable Nanosponge-Loaded Pluronic F127 Hydrogel for Pore-Forming Toxin Neutralization

An injectable composite hydrogel containing polydopamine-coated curcumin nanoparticles and indoximod for the enhanced combinational chemo-photothermal-immunotherapy of breast tumors

The complexity and compensatory evolution of tumors weaken the effectiveness of single antitumor therapies. Therefore, multimodal combination therapies hold great promise in defeating tumors. Herein, we constructed a multi-level regulatory co-delivery system based on chemotherapy, phototherapy, and immunotherapy. Briefly, curcumin (Cur) was prepared as nanoparticles and coated with polydopamine (PDA) to form PCur-NPs, which along with an immune checkpoint inhibitor (indoximod, IND) were then loaded into a thermosensitive Pluronic F127 (F127) hydrogel to form a multifunctional nanocomposite hydrogel (PCur/IND@Gel). The in situ-formed hydrogel exhibited excellent photothermal conversion efficiency and sustained drug release behavior both in vitro and in vivo. In addition, PCur-NPs showed enhanced cellular uptake and cytotoxicity under NIR laser irradiation and induced potent immunogenic cell death (ICD). After intratumoral injection of PCur/IND@Gel, significant apoptosis in 4T1 tumors was induced, dendritic cells in lymph nodes were highly activated, potent CD8+ and CD4+ antitumor immune responses were elicited and regulative T cells in tumors were significantly reduced, which notably inhibited the tumor growth and prolonged the survive time of 4T1 tumor-bearing mice. Therefore, this injectable nanocomposite hydrogel is a promising drug co-delivery platform for chemo-photothermal-immunotherapy of breast tumors.

Antimicrobial potential of a biosurfactant gel for the prevention of mixed biofilms formed by fluconazole-resistant C. albicans and methicillin-resistant S. aureus in catheters

Dual-species biofilms formed by Candida albicans and Staphylococcus aureus have high virulence and drug resistance. In this context, biosurfactants produced by Pseudomonas aeruginosa have been widely studied, of which a new derivative (RLmix_Arg) stands out for possible application in formulations. The objective of this study was to evaluate the antibiofilm activity of RLmix_Arg, both alone and incorporated in a gel prepared with Pluronic F-127, against dual-species biofilms of fluconazole-resistant C. albicans (FRCA) and methicillin-resistant S. aureus (MRSA) in impregnated catheters. Broth microdilution tests, MTT reduction assays of mature biofilms, impregnation of RLmix_Arg and its gel in peripheral venous catheters, durability tests and scanning electron microscopy (SEM) were performed. RLmix_Arg showed antimicrobial activity against Candida spp. and S. aureus, by reducing the cell viability of mixed biofilms of FRCA and MRSA, and preventing their formation in a peripheral venous catheter. The incorporation of this biosurfactant in the Pluronic F-127 gel considerably enhanced its antibiofilm activity. Thus, RLmix_Arg has potential application in gels for impregnation in peripheral venous catheters, helping to prevent development of dual-species biofilms of FRCA and MRSA.

Magnetically controlled nanorobots induced oriented and rapid clearance of the cytokine storm for acute lung injury therapy

Cytokine storms characterized by excessive secretion of circulating cytokines and immune-cell hyperactivation are life-threatening systemic inflammatory syndromes. The new strategy is in great demand to inhibit the cytokine storm. Here, we designed a type of magnetically controlled nanorobots (MAGICIAN) by fusing neutrophil membranes onto Fe3O4 nanoparticles (Fe3O4NPs). In our study, the receptors of neutrophil membranes were successfully coated to the surface of Fe3O4NPs. The associated membrane functions of neutrophils were highly preserved. MAGICIAN could in vitro neutralize the inflammatory cytokines including interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ). Interestingly, MAGICIAN could be navigated to the liver sites under magnetic control and accelerated the cytokine clearance by the liver. Administration of MAGICIAN could efficiently relieve the inflammation in the acute lung injury mouse model. In addition, MAGICIAN displayed good biosafety in systemic administration. The present study provides a safe and convenient approach for the clearance of cytokine storms, indicating the potential for clinical application in acute lung injury therapy.

Injectable thermogel incorporating reactive oxygen species scavenger and nitric oxide donor to accelerate the healing process of diabetic wounds

The healing of diabetic wounds is challenging due to redox imbalances. Herein, the thermogelling system AR-ACP hydrogel, with encapsulated biosafe nitric oxide (NO) donor L-arginine and resveratrol as an ROS scavenger, is established for sustainable wound therapy in the diabetic state. The innovated AR-ACP hydrogel dressings shows the sol-gel transition at 34 °C, allowing the hydrogel to fully cover wounds. The combination of L-arginine and resveratrol showed a prominent effect on anti-oxidative activity. The elimination of superoxide anions from the activated immune cells/oxidative cells by resveratrol maintained the NO-proangiogenic factors generated from L-arginine. Furthermore, the AR-ACP hydrogel endowed outstanding features such as haemocompatibility, non-skin irradiation as well as antibacterial activity. In the in vivo diabetic mice model, complete epidermal regeneration comparable to undamaged skin was observed with AR-ACP hydrogel. The synergy between L-arginine and resveratrol in the ACP hydrogel facilitated neovascularisation in the early stage, resulting in the higher balance in cellularity growth and collagen deposition in the dermal layer compared to control groups. Taken together, our findings demonstrate that the use of a customised ACP-based hydrogel, with the additional L-arginine and resveratrol, resulted in significant skin regeneration in the diabetic state.

Progress in Pluronic F127 Derivatives for Application in Wound Healing and Repair

Pluronic F127 hydrogel biomaterial has garnered considerable attention in wound healing and repair due to its remarkable properties including temperature sensitivity, injectability, biodegradability, and maintain a moist wound environment. This comprehensive review provides an in-depth exploration of the recent advancements in Pluronic F127-derived hydrogels, such as F127-CHO, F127-NH2, and F127-DA, focusing on their applications in the treatment of various types of wounds, ranging from burns and acute wounds to infected wounds, diabetic wounds, cutaneous tumor wounds, and uterine scars. Furthermore, the review meticulously examines the intricate interaction mechanisms employed by these hydrogels within the wound microenvironment. By elucidating the underlying mechanisms, discussing the strengths and weaknesses of Pluronic F127, analyzing the current state of wound healing development, and expanding on the trend of targeting mitochondria and cells with F127 as a nanomaterial. The review enhances our understanding of the therapeutic effects of these hydrogels aims to foster the development of effective and safe wound-healing modalities. The valuable insights provided this review have the potential to inspire novel ideas for clinical treatment and facilitate the advancement of innovative wound management approaches.

Triptolide with hepatotoxicity and nephrotoxicity used in local delivery treatment of myocardial infarction by thermosensitive hydrogel

Myocardial infarction (MI) resulting from coronary artery occlusion is the leading global cause of cardiovascular disability and mortality. Anti-inflammatory treatment plays an important role in MI treatment. Triptolide (TPL), as a Chinese medicine monomer, has a variety of biological functions, including anti-inflammatory, anti-tumor, and immunoregulation. However, it has been proved that TPL is poorly water soluble, and has clear hepatotoxicity and nephrotoxicity, which seriously limits its clinical application. Herein, we designed a long-acting hydrogel platform (TPL@PLGA@F127) for MI treatment by intramyocardial injection. First, we found that the inflammatory response and immune regulation might be the main mechanisms of TPL against MI by network pharmacology. Subsequently, we prepared the hydrogel platform (TPL@PLGA@F127) and tested its effects and toxicity on normal organs in the early stage of MI (3 days after MI-operation). The results showed that TPL@PLGA@F127 could not only promote "repair" macrophages polarization (to M2 macrophage) by day 3 after MI, but also has a long-lasting anti-inflammatory effect in the later stage of MI (28 days after MI-operation). Additionally, we proved that TPL@PLGA@F127 could attenuate the toxicity of TPL by releasing it more slowly and stably. Finally, we observed the long-term effects of TPL@PLGA@F127 on MI and found that it could improve cardiac function, depress the myocardial fibrosis and protect the cardiomyocytes. In summary, this study indicated that TPL@PLGA@F127 could not only enhance the therapeutic effects of TPL on MI, but also attenuate the hepatotoxicity and nephrotoxicity, which established a strong foundation for the clinical application of TPL for MI.

Design Strategies for Cellular Nanosponges as Medical Countermeasures

The interest in using therapeutic nanoparticles to bind with harmful molecules or pathogens and subsequently neutralize their bioactivity has grown tremendously. Among various nanomedicine platforms, cell membrane-coated nanoparticles, namely, "cellular nanosponges," stand out for their broad-spectrum neutralization capability challenging to achieve in traditional countermeasure technologies. Such ability is attributable to their cellular function-based rather than target structure-based working principle. Integrating cellular nanosponges with various synthetic substrates further makes their applications exceptionally versatile and adaptive. This review discusses the latest cellular nanosponge technology focusing on how the structure-function relationship in different designs has led to versatile and potent medical countermeasures. Four design strategies are discussed, including harnessing native cell membrane functions for biological neutralization, functionalizing cell membrane coatings to enhance neutralization capabilities, combining cell membranes and functional cores for multimodal neutralization, and integrating cellular nanosponges with hydrogels for localized applications. Examples in each design strategy are selected, and the discussion is to highlight their structure-function relationships in complex disease settings. The review may inspire additional design strategies for cellular nanosponges and fulfill even broader medical applications.

Biomedical Nanosystems for In Vivo Detoxification: From Passive Delivery Systems to Functional Nanodevices and Nanorobots

The problem of low efficiency of nanotherapeutic drugs challenges the creation of new alternative biomedical nanosystems known as robotic nanodevices. In addition to encapsulating properties, nanodevices can perform different biomedical functions, such as precision surgery, in vivo detection and imaging, biosensing, targeted delivery, and, more recently, detoxification of endogenous and xenobiotic compounds. Nanodevices for detoxification are aimed at removing toxic molecules from biological tissues, using a chemical- and/or enzyme-containing nanocarrier for the toxicant to diffuse inside the nanobody. This strategy is opposite to drug delivery systems that focus on encapsulating drugs and releasing them under the influence of external factors. The review describes various kinds of nanodevices intended for detoxification that differ by the type of poisoning treatment they provide, as well as the type of materials and toxicants. The final part of the review is devoted to enzyme nanosystems, an emerging area of research that provides fast and effective neutralization of toxins in vivo.

Recent advances of cell membrane-coated nanoparticles for therapy of bacterial infection

The rapid evolution of antibiotic resistance and the complicated bacterial infection microenvironments are serious obstacles to traditional antibiotic therapy. Developing novel antibacterial agents or strategy to prevent the occurrence of antibiotic resistance and enhance antibacterial efficiency is of the utmost importance. Cell membrane-coated nanoparticles (CM-NPs) combine the characteristics of the naturally occurring membranes with those of the synthetic core materials. CM-NPs have shown considerable promise in neutralizing toxins, evading clearance by the immune system, targeting specific bacteria, delivering antibiotics, achieving responsive antibiotic released to the microenvironments, and eradicating biofilms. Additionally, CM-NPs can be utilized in conjunction with photodynamic, sonodynamic, and photothermal therapies. In this review, the process for preparing CM-NPs is briefly described. We focus on the functions and the recent advances in applications of several types of CM-NPs in bacterial infection, including CM-NPs derived from red blood cells, white blood cells, platelet, bacteria. CM-NPs derived from other cells, such as dendritic cells, genetically engineered cells, gastric epithelial cells and plant-derived extracellular vesicles are introduced as well. Finally, we place a novel perspective on CM-NPs' applications in bacterial infection, and list the challenges encountered in this field from the preparation and application standpoint. We believe that advances in this technology will reduce threats posed by bacteria resistance and save lives from infectious diseases in the future.

Intelligent Hydrogels in Myocardial Regeneration and Engineering

Myocardial infarction (MI) causes impaired cardiac function due to the loss of cardiomyocytes following an ischemic attack. Intelligent hydrogels offer promising solutions for post-MI cardiac tissue therapy to aid in structural support, contractility, and targeted drug therapy. Hydrogels are porous hydrophilic matrices used for biological scaffolding, and upon the careful alteration of ideal functional groups, the hydrogels respond to the chemistry of the surrounding microenvironment, resulting in intelligent hydrogels. This review delves into the perspectives of various intelligent hydrogels and evidence from successful models of hydrogel-assisted treatment strategies.

Application of Nanomaterials in the Prevention, Detection, and Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA)

Due to differences in geographic surveillance systems, chemical sanitization practices, and antibiotic stewardship (AS) implementation employed during the COVID-19 pandemic, many experts have expressed concerns regarding a future surge in global antimicrobial resistance (AMR). A potential beneficiary of these differences is the Gram-positive bacteria MRSA. MRSA is a bacterial pathogen with a high potential for mutational resistance, allowing it to engage various AMR mechanisms circumventing conventional antibiotic therapies and the host’s immune response. Coupled with a lack of novel FDA-approved antibiotics reaching the clinic, the onus is on researchers to develop alternative treatment tools to mitigate against an increase in pathogenic resistance. Mitigation strategies can take the form of synthetic or biomimetic nanomaterials/vesicles employed in vaccines, rapid diagnostics, antibiotic delivery, and nanotherapeutics. This review seeks to discuss the current potential of the aforementioned nanomaterials in detecting and treating MRSA.

Dithiocarbazate-copper complex loaded thermosensitive hydrogel for lung cancer therapy via tumor in situ sustained-release

The Pluronic F127 thermosensitive hydrogels containing copper complex 3 were constructed, which could delay A549 tumor xenograft growth effectively with lower systemic toxicity.