pH-activatable oxidative stress amplifying dissolving microneedles for combined chemo-photodynamic therapy of Melanoma

Dissolving microneedles for melanoma: Most recent updates, challenges, and future perspectives

Skin cancer is one among the common types of cancers, affecting millions of individual globally. The conventional anticancer therapy such as chemotherapy results in worst systemic and local side effects as well as inhibit the growth of healthy cells around the tumor cells. Dissolving microneedles (DMNs) is a groundbreaking technology with less invasive and more targeted features. Physically, these tiny dissolving needles deliver the anticancer payloads drug to the tumor site after its direct application on the skin surface. Specifically, the DMNs release the anticancer drug cargoes into the cancerous cell sparing the healthy cells around the tumor, thus has provided a significant contribution in the landscape of traditional skin cancer therapy. This targeted therapeutic approach of dissolving microneedles shows a significant therapeutic outcome in decreasing the growth of cancer cells in pre-clinical studies. Dissolving microneedles (DMNs) have demonstrated effectiveness in the targeted delivery of drugs, genes, and vaccines specifically at the site of skin tumors. This method mimics the localized release of adjuvants and immunomodulators, leading to significant humoral and cellular immune responses that are beneficial for skin cancer therapy. In this review, the current trends and potential roles of dissolving microneedles in delivering therapeutic agents focused on treating skin melanoma have been highlighted, drawing insights from recent literature. This emphasizes the promising applications of DMNs in enhancing treatment outcomes for skin cancer patients. Lastly, future perspectives were identified for improving the therapeutic potential and translation of DMNs into clinic.

ROS Regulation in CNS Disorder Therapy: Unveiling the Dual Roles of Nanomedicine

The treatment of brain diseases has always been the focus of attention. Due to the presence of the blood-brain barrier (BBB), most small molecule drugs are difficult to reach the brain, leading to undesirable therapeutic outcomes. Recently, nanomedicines that can cross the BBB and precisely target lesion sites have emerged as thrilling tools to enhance the early diagnosis and treat various intractable brain disorders. Extensive research has shown that reactive oxygen species (ROS) play a crucial role in the occurrence and progression of brain diseases, including brain tumors and neurodegenerative diseases (NDDs) such as Alzheimer's disease, Parkinson's disease, stroke, or traumatic brain injury, making ROS a potential therapeutic target. In this review, on the structure and function of BBB as well as the mechanisms are first elaborated through which nanomedicine traverses it. Then, recent studies on ROS production are summarized through photodynamic therapy (PDT), chemodynamic therapy (CDT), and sonodynamic therapy (SDT) for treating brain tumors, and ROS depletion for treating NDDs. This provides valuable guidance for the future design of ROS-targeted nanomedicines for brain disease treatment. The ongoing challenges and future perspectives in developing nanomedicine-based ROS management for brain diseases are also discussed and outlined.

Microneedles as a Promising Technology for Disease Monitoring and Drug Delivery: A Review

The delivery of molecules, such as DNA, RNA, peptides, and certain hydrophilic drugs, across the epidermal barrier poses a significant obstacle. Microneedle technology has emerged as a prominent area of focus in biomedical research because of its ability to deliver a wide range of biomolecules, vaccines, medicines, and other substances through the skin. Microneedles (MNs) form microchannels by disrupting the skin's structure, which compromises its barrier function, and facilitating the easy penetration of drugs into the skin. These devices enhance the administration of many therapeutic substances to the skin, enhancing their stability. Transcutaneous delivery of medications using a microneedle patch offers advantages over conventional drug administration methods. Microneedles containing active substances can be stimulated by different internal and external factors to result in the regulated release of the substances. To achieve efficient drug administration to the desired location, it is necessary to consider the design of needles with appropriate optimized characteristics. The choice of materials for developing and manufacturing these devices is vital in determining the pharmacodynamics and pharmacokinetics of drug delivery. This article provides the most recent update and overview of the numerous microneedle systems that utilize different activators to stimulate the release of active components from the microneedles. Further, it discusses the materials utilized for producing microneedles and the design strategies important in managing the release of drugs. An explanation of the commonly employed fabrication techniques in biomedical applications and electronics, particularly for integrated microneedle drug delivery systems, is discussed. To successfully implement microneedle technology in clinical settings, it is essential to comprehensively assess several factors, such as biocompatibility, drug stability, safety, and production cost. Finally, an in-depth review of these criteria and the difficulties and potential future direction of microneedles in delivering drugs and monitoring diseases is explored.

A stimulus responsive microneedle-based drug delivery system for cancer therapy

The intricate nature of the tumor microenvironment (TME) results in the inefficient delivery of anticancer drugs within tumor tissues, significantly compromising the therapeutic effect of cancer treatment. To address this issue, transdermal drug delivery microneedles (MNs) with high mechanical strength have emerged. Such MNs penetrate the skin barrier, enabling efficient drug delivery to tumor tissues. This approach enhances drug bioavailability, while also mitigating concerns such as liver and kidney toxicity associated with intravenous and oral drug administration. Notably, stimulus responsive MNs designed for drug delivery have the capacity to respond to various biological signals and pathological changes. This adaptability enables them to exert therapeutic effects within the TME, exploiting biochemical variations and tailoring treatment strategies to suit tumor characteristics. The present review surveys recent advancements in responsive MN systems. This comprehensive analysis serves as a valuable reference for the prospective application of smart MN drug delivery systems in cancer therapy.

Alkyl chain length-regulated in situ intelligent nano-assemblies with AIE-active photosensitizers for photodynamic cancer therapy

Photodynamic therapy (PDT) brings new hope for the treatment of breast cancer due to few side effects and highly effective cell killing; however, the low bioavailability of traditional photosensitizers (PSs) and their dependence on oxygen severely limits their application. Aggregation-induced emission (AIE) PSs can dramatically facilitate the photosensitization effect, which can have positive impacts on tumor PDT. To-date, most AIE PSs lack tumor targeting capability and possess poor cell delivery, resulting in their use in large quantities that are harmful to healthy tissues. In this study, a series of AIE PSs based on pyridinium-substituted triphenylamine salts ( TTPAs 1-6) with different alkyl chain lengths are synthesized. Results reveal that TTPAs 1-6 promote the generation of type I and II ROS, including ·OH and 1O2. In particular, the membrane permeability and targeting of TTPAs 4-6 bearing C8-C10 side-chains are higher than TTPAs 1-3 bearing shorter alkyl chains. Additionally, they can assemble with albumin, thereby forming nanoparticles (TTPA 4-6 NPs) in situ in blood, which significantly facilitates mitochondrial-targeting and strong ROS generation ability. Moreover, the TTPA 4-6 NPs are pH-responsive, allowing for increased accumulation or endocytosis of the tumor and enhancing the imaging or therapeutic effect. Therefore, the in vivo distributions of TTPA 4-6 NPs are visually enriched in tumor sites and exhibited excellent PDT efficacy. This work demonstrates a novel strategy for AIE PDT and has the potential to play an essential role in clinical applications using nano-delivery systems.

Dissolving microneedles: standing out in melanoma treatment

Melanoma is one of the most significant and dangerous superficial skin tumors with a high fatality rate, thanks to its high invasion rate, drug resistance and frequent metastasis properties. Unfortunately, researchers for decades have demonstrated that the outcome of using conventional therapies like chemotherapy and immunotherapy with normal drug delivery routes, such as an oral route to treat melanoma was not satisfactory. The severe adverse effects, slow drug delivery efficiency and low drug accumulation at targeted malignancy sites all lead to poor anti-cancer efficacy and terrible treatment experience. As a novel transdermal drug delivery system, microneedles (MNs) have emerged as an effective solution to help improve the low cure rate of melanoma. The excellent characteristics of MNs make it easy to penetrate the stratum corneum (SC) and then locally deliver the drug towards the lesion without drug leakage to mitigate the occurrence of side effects and increase the drug accumulation. Therefore, loading chemotherapeutic drugs or immunotherapy drugs in MNs can address the problems mentioned above, and MNs play a crucial role in improving the curative effect of conventional treatment methods. Notably, novel tumor therapies like photothermal therapy (PTT), photodynamic therapy (PDT) and chemodynamic therapy (CDT) have shown good application prospects in the treatment of melanoma, and MNs provide a valid platform for the combination of conventional therapies and novel therapies by encompassing different therapeutic materials in the matrix of MNs. The synergistic effect of multiple therapies can enhance the therapeutic efficacy compared to single therapies, showing great potential in melanoma treatment. Dissolving MNs have been the most commonly used microneedles in the treatment of melanoma in recent years, mainly because of their simple fabrication procedure and enough drug loading. So, considering the increasing use of dissolving MNs, this review collects research studies published in the last four years (2020-2024) that have rarely been included in other reviews to update the progress of applications of dissolving MNs in anti-melanoma treatment, especially in synergistic therapies. This review also presents current design and fabrication methods of dissolving MNs; the limitations of microneedle technology in the treatment of melanoma are comprehensively discussed. This review can provide valuable guidance for their future development.

Topical Delivery of Dual Loaded Nano-Transfersomes Mediated Chemo-Photodynamic Therapy against Melanoma via Inducing Cell Cycle Arrest and Apoptosis

Melanoma is a malignant skin cancer associated with high mortality rates and drug resistance, posing a significant threat to human health. The combination of chemotherapy and photodynamic therapy (PDT) represents a promising strategy to enhance antitumor efficacy through synergistic anti-cancer effects. Topical delivery of chemotherapeutic drugs and photosensitizers (PS) offers a non-invasive and safe way to treat melanoma. However, the effectiveness of these treatments is often hindered by challenges such as limited skin permeability and instability of the PS. In this study, transfersomes (TFS) were designed to facilitate transdermal delivery of the chemotherapeutic drug 5-Fluorouracil (5-FU) and the PS Imperatorin (IMP) for combined chemo-photodynamic therapy for melanoma. The cytotoxic and phototoxic effects of TFS-mediated PDT (TFS-UVA) were investigated in A375 cells and nude mice. The study also demonstrated that TFS-UVA generated intracellular ROS, induced G2/ M phase cell cycle arrest, and promoted cell apoptosis. In conclusion, this study indicated that 5-FU/ IMP-TFS serves as an effective transdermal therapeutic strategy for chemo-PDT in treating melanoma.

Nanocomposite hydrogel microneedles: a theranostic toolbox for personalized medicine

Due to the severity and high prevalence of cancer, as well as its complex pathological condition, new strategies for cancer treatment and diagnostics are required. As such, it is important to design a toolbox that integrates multiple functions on a single smart platform. Theranostic hydrogels offer an innovative and personalized method to tackle cancer while also considering patient comfort, thereby facilitating future implementation and translation to the clinic. In terms of theranostic systems used in cancer therapy, nanoparticles are widely used as diagnostic and therapeutic tools. Nanoparticles can achieve systemic circulation, evade host defenses, and deliver drugs and signaling agents at the targeted site, to diagnose and treat the disease at a cellular and molecular level. In this context, hydrogel microneedles have a high potential for multifunctional operation in medical devices, while avoiding the complications associated with the systemic delivery of therapeutics. Compared with oral administration and subcutaneous injection, microneedles offer advantages such as better patient compliance, faster onset of action, and improved permeability and efficacy. In addition, they comprise highly biocompatible polymers with excellent degradability and tunable properties. Nanoparticles and microneedles thus offer the possibility to expand the theranostic potential through combined synergistic use of their respective features. We review herein recent advances concerning processing methods and material requirements within the realm of hydrogel microneedles as theranostic platforms, various approaches toward cancer therapy, and the incorporation of nanoparticles for added functionality.

Small molecule-engineered nanoassembly for lipid peroxidation-amplified photodynamic therapy

Photodynamic therapy (PDT), extensively explored as a non-invasive and spatio-temporal therapeutic modality for cancer treatment, encounters challenges related to the brief half-life and limited diffusion range of singlet oxygen. Lipid peroxides, formed through the oxidation of polyunsaturated fatty acids by singlet oxygen, exhibit prolonged half-life and potent cytotoxicity. Herein, we employed small molecule co-assembly technology to create nanoassemblies of pyropheophorbide a (PPa) and docosahexaenoic acid (DHA) to bolster PDT. DHA, an essential polyunsaturated fatty acid, co-assembled with PPa to generate nanoparticles (PPa@DHA NPs) without the need for additional excipients. To enhance the stability of these nanoassemblies, we introduced 20% DSPE-PEG2k as a stabilizing agent, leading to the formation of PPa@DHA PEG2k NPs. Upon laser irradiation, PPa-produced singlet oxygen swiftly oxidized DHA, resulting in the generation of cytotoxic lipid peroxides. This process significantly augmented the therapeutic efficiency of PDT. Consequently, tumor growth was markedly suppressed, attributed to the sensitizing and amplifying impact of DHA on PDT in a 4T1 tumor-bearing mouse model. In summary, this molecule-engineered nanoassembly introduces an innovative co-delivery approach to enhance PDT with polyunsaturated fatty acids.

Spatiotemporal fate of nanocarriers-embedded dissolving microneedles: the impact of needle dissolving rate

OBJECTIVE

Dissolving microneedles (DMNs) have shown great potential for transdermal drug delivery due to their excellent skin-penetrating ability and combination with nanocarriers (NCs) can realize targeted drug delivery. The objective of this study was to investigate the impact of microneedle dissolving rate on the in vivo fate of NC-loaded DMNs, which would facilitate the clinical translation of such systems.

METHODS

Solid lipid nanoparticles (SLNs) were selected as the model NC for loading in DMNs, which were labeled by P4 probes with aggregation-quenching properties. Sodium hyaluronate acid (HA) and chitosan (CS), with different aqueous dissolving rates, were chosen as model tip materials. The effects of needle dissolving rate on the in vivo fate of NC-loaded DMNs was investigated by tracking the distribution of fluorescence signals after transdermal exposure.

RESULTS

P4 SLNs achieved a deeper diffusion depth of 180 μm in DMN-HA with a faster dissolution rate, while the diffusion depth in DMN-CS with a slower dissolution rate was lower (140 μm). The in vivo experiments demonstrated that P4 SLNs had a T1/2 value of 12.14 h in DMN-HA, whilst a longer retention time was found in DMN-CS, with a T1/2 of 13.12 h.

CONCLUSIONS

This study confirmed that the in vivo diffusion rate of NC-loaded DMNs was determined by the dissolving rate of DMNs materials and provided valuable guidance for the design and development of NC-loaded DMNs in the future.

Microneedles Based on a Biodegradable Polymer-Hyaluronic Acid

Transdermal transport can be challenging due to the difficulty in diffusing active substances through the outermost layer of the epidermis, as the primary function of the skin is to protect against the entry of exogenous compounds into the body. In addition, penetration of the epidermis for substances hydrophilic in nature and particles larger than 500 Da is highly limited due to the physiological properties and non-polar nature of its outermost layer, namely the stratum corneum. A solution to this problem can be the use of microneedles, which "bypass" the problematic epidermal layer by dispensing the active substance directly into the deeper layers of the skin. Microneedles can be obtained with various materials and come in different types. Of special interest are carriers based on biodegradable and biocompatible polymers, such as polysaccharides. Therefore, this paper reviews the latest literature on methods to obtain hyaluronic acid-based microneedles. It focuses on the current advancements in this field and consequently provides an opportunity to guide future research in this area.

ROS-responsive sprayable hydrogel as ROS scavenger and GATA6+ macrophages trap for the prevention of postoperative abdominal adhesions

Postoperative abdominal adhesions are a common clinical problem after surgery and can cause many serious complications. Current most commonly used antiadhesion products are less effective due to their short residence time and focus primary on barrier function. Herein, we developed a sprayable hydrogel barrier (sHA-ADH/OHA-E) with self-regulated drug release based on ROS levels at the trauma site, to serve as a smart inflammatory microenvironment modulator and GATA6+ macrophages trap for non-adherent recovery from abdominal surgery. Sulfonated hyaluronic acid (HA) conjugates modified with adipic dihydrazide (sHA-ADH), and oxidized HA conjugates grafted with epigallocatechin-3-gallate (EGCG) via ROS-cleavable boronate bonds (OHA-E) were synthesized. sHA-ADH/OHA-E hydrogel was facilely fabricated within 5 s after simply mixing sHA-ADH and OHA-E through forming dynamic covalent acylhydrazones. With good biocompatibility, appropriate mechanical strength, tunable shear-thinning, self-healing, asymmetric adhesion, and reasonable in vivo retention time, sHA-ADH/OHA-E hydrogel meets the requirements of a perfect physical barrier. Intriguingly, sulfonic acid groups endowed the hydrogel with satisfactory anti-fibroblast and macrophage attachment capability, and were demonstrated for the first time to act as polyanion traps to prevent GATA6+ macrophages aggregation. Importantly, EGCG could be intelligently released by ROS triggering to alleviate oxidative stress and promote proinflammatory M1 macrophage polarize to antiinflammatory M2 phenotype. Further, the fibrinolytic system balance was restored to reduce fibrosis. Thanks to the above advantages, the sHA-ADH/OHA-E hydrogel exhibited excellent anti-adhesion effects in a rat sidewall defect-cecum abrasion model and is expected to be a promising and clinically translatable antiadhesion barrier.

Glucose-responsive insulin microneedle patches for long-acting delivery and release visualization

Limited drug loading and incomplete drug release are two major obstacles that traditional polymeric microneedles (MNs) have to overcome. For smart controlled-release MNs, since drug release duration is uncertain, a clear indication of the finish of drug release is also important for patient guidance on the timing of the next dose. In this study, MN with a triple structure of a glucose-responsive shell, loaded insulin powders and a colored propelling inner core (inspired by the mechanism of osmotic pump) was innovatively constructed. The MN patch could release insulin according to blood glucose levels (BGLs) and had excellent drug loading, more complete drug release, and good drug stability, which significantly prolonged the normoglycemic time. An approximately 0.3 cm2 patch has a hypoglycemic effect on diabetic mice for up to 24 h. Moreover, the fading of the inner core could indicate the release process of the loaded drug and can help to facilitate uninterrupted closed loop therapy for patients. The designed triple MN structure is also suitable, and can be used in the design of other smart MN drug delivery systems to further improve their drug loading capacity and simultaneously achieve more complete, smart controlled and visualized drug release.

Self-healing hydrogels based on biological macromolecules in wound healing: A review

The complete healing of skin wounds has been a challenge in clinical treatment. Self-healing hydrogels are special hydrogels formed by distinctive physicochemically reversible bonds, and they are considered promising biomaterials in the biomedical field owing to their inherently good drug-carrying capacity as well as self-healing and repair abilities. Moreover, natural polymeric materials have received considerable attention in skin tissue engineering owing to their low cytotoxicity, low immunogenicity, and excellent biodegradation rates. In this paper, we review recent advances in the design of self-healing hydrogels based on natural polymers for skin-wound healing applications. First, we outline a variety of natural polymers that can be used to construct self-healing hydrogel systems and highlight the advantages and disadvantages of different natural polymers. We then describe the principle of self-healing hydrogels in terms of two different crosslinking mechanisms-physical and chemical-and dissect their performance characteristics based on the practical needs of skin-trauma applications. Next, we outline the biological mechanisms involved in the healing of skin wounds and describe the current application strategies for self-healing hydrogels based on these mechanisms. Finally, we analyze and summarize the challenges and prospects of natural-material-based self-healing hydrogels for skin applications.

CRABP2 regulates infiltration of cancer-associated fibroblasts and immune response in melanoma

Finding biomarkers for immunotherapy is an urgent issue in cancer treatment. Cellular retinoic acid-binding protein 2 (CRABP2) is a controversial factor in the occurrence and development of human tumors. However, there is limited research on the relationship between CRABP2 and immunotherapy response. This study found that negative correlations of CRABP2 and immune checkpoint markers (PD-1, PD-L1, and CTLA-4) were observed in breast invasive carcinoma (BRCA), skin cutaneous melanoma (SKCM), stomach adenocarcinoma (STAD) and testicular germ cell tumors (TGCT). In particular, in SKCM patients who were treated with PD-1 inhibitors, high levels of CRABP2 predicted poor prognosis. Additionally, CRABP2 expression was elevated in cancer-associated fibroblasts (CAFs) at the single-cell level. The expression of CRABP2 was positively correlated with markers of CAFs, such as MFAP5, PDPN, ITGA11, PDGFRα/β and THY1 in SKCM. To validate the tumor-promoting effect of CRABP2 in vivo, SKCM xenograft mice models with CRABP2 overexpression have been constructed. These models showed an increase in tumor weight and volume. Enrichment analysis indicated that CRABP2 may be involved in immune-related pathways of SKCM, such as extracellular matrix (ECM) receptor interaction and epithelial-mesenchymal transition (EMT). The study suggests that CRABP2 may regulate immunotherapy in SKCM patients by influencing infiltration of CAFs. In conclusion, this study provides new insights into the role of CRABP2 in immunotherapy response. The findings suggest that CRABP2 may be a promising biomarker for PD-1 inhibitors in SKCM patients. Further research is needed to confirm these findings and to explore the clinical implications of CRABP2 in immunotherapy.

Tailoring Hyaluronic Acid Hydrogels for Biomedical Applications

Hyaluronic acid (HA) is an attractive anionic polysaccharide polymer with inherent pharmacological properties and versatile chemical groups for modification. Due to their water retention ability, biocompatibility, biodegradation, cluster of differentiation‐44 targeting, and highly designable capacity, HA hydrogels have been an emerging biomaterial, showing tailoring performance in terms of chemical modifications and hydrogel forms. Various preparation technologies have been developed for the fabrication of the tailoring HA hydrogels with unique structures and functions. They have been utilized in diverse biomedical applications like drug delivery and tissue engineering scaffolds. Herein, this review comprehensively summarizes the HA derivatives with different molecule weights and functional modifications. Then the various fabrication methods to obtain tailoring hydrogels in the forms of nanogel, nanofiber, microparticle, microneedle patch, injectable hydrogel, and scaffold are reviewed as well. The emphasis is focused on the shining biomedical applications of these tailoring HA hydrogels in anti‐bacteria, anti‐inflammation, wound healing, cancer treatment, regenerative medicine, psoriasis treatment, diagnosis, etc. The potentials and prospects are subsequently given to inspire further investigation, aiming at accelerating product translation from research to clinic.

Hydrogel-Based Microneedle as a Drug Delivery System

The skin is considered the largest and most accessible organ in the human body, and allows the use of noninvasive and efficient strategies for drug administration, such as the transdermal drug delivery system (TDDS). TDDSs are systems or patches, with the ability and purpose to deliver effective and therapeutic doses of drugs through the skin. Regarding the specific interaction between hydrogels (HG) and microneedles (MNs), we seek to find out how this combination would be applied in the context of drug delivery, and we detail some possible advantages of the methods used. Depending on the components belonging to the HG matrix, we can obtain some essential characteristics that make the combination of hydrogels-microneedles (HG-MNs) very advantageous, such as the response to external stimuli, among others. Based on multiple characteristics provided by HGMNs that are depicted in this work, it is possible to obtain unique properties that include controlled, sustained, and localized drug release, as well as the possibility of a synergistic association between the components of the formulation and the combination of more than one bioactive component. In conclusion, a system based on HG-MNs can offer many advantages in the biomedical field, bringing to light a new technological and safe system for improving the pharmacokinetics and pharmacodynamics of drugs and new treatment perspectives.

Dissolving microneedles-based programmed delivery system for enhanced chemo-immunotherapy of melanoma

Immune checkpoint blockade, especially the programmed cell death ligand 1 (PD-L1) blockade, has revolutionized the treatment of melanoma. However, PD-1/PD-L1 monotherapy leads to unsatisfactory therapeutic outcomes. The immunotherapy of melanoma could be improved by adding doxorubicin (DOX), which triggers immunogenic cell death (ICD) effect to activate anti-tumor immunity. Additionally, microneedles, especially dissolving microneedles (dMNs), can further enhance outcomes of chemo-immunotherapy due to the physical adjuvant effect of dMNs. Herein, we developed the dMNs-based programmed delivery system that incorporated pH-sensitive and melanoma-targeting liposomes to co-deliver DOX and siPD-L1, achieving enhanced chemo-immunotherapy of melanoma (si/DOX@LRGD dMNs). The incorporated si/DOX@LRGD LPs demonstrated uniform particle size, pH-sensitive drug release, high in vitro cytotoxicity and targeting ability. Besides, si/DOX@LRGD LPs effectively downregulated the expression of PD-L1, induced tumor cell apoptosis and triggered ICD effect. The si/DOX@LRGD LPs also showed deep penetration (approximately 80 μm) in 3D tumor spheroids. Moreover, si/DOX@LRGD dMNs dissolved rapidly into the skin and had sufficient mechanical strength to penetrate skin, reaching a depth of approximately 260 μm in mice skin. In mice model of melanoma tumor, si/DOX@LRGD dMNs exhibited better anti-tumor efficacy than monotherapy by dMNs and tail intravenous injection at the same dose. This was due to the higher cytotoxic CD8+ T cells and the secreted cytotoxic cytokine IFN-γ evoked by si/DOX@LRGD dMNs, thereby eliciting strong T-cell mediated immune response and resulted in enhanced anti-tumor effects. In conclusion, these findings suggested that si/DOX@LRGD dMNs provided a promising and effective strategy for enhanced chemo-immunotherapy of melanoma.

Preparation and Properties of Polyvinylpyrrolidone/Sodium Carboxymethyl Cellulose Soluble Microneedles

Transdermal drug delivery is a new means of delivering drugs through the skin to achieve therapeutic effects. Microneedles have several advantages, including low cost, easy self-administration, and high delivery efficiency. Different polymers affect the morphology, mechanical properties, and drug delivery efficiency of microneedles. To study the performance and limitations of microneedles (MNs), we prepared different ratios of polymers. MNs were fabricated from polyvinylpyrrolidone (PVP) and sodium carboxymethyl cellulose (CMC-Na) using the centrifugal molding method. Needle morphology, formability, and other properties of the polymers were evaluated to compare the performances of MNs with different ratios. PVP and CMC-Na were intermixed at different ratios with water as the solvent. The soluble MNs were prepared by mold casting. The morphology, thermodynamic properties, and crystallinity were studied using scanning electron microscopy (SEM), thermogravimetric analysis (TG), differential scanning calorimetric analysis (DSC), and X-ray diffraction (XRD). The results showed that composite microneedles have good thermal stability. Among the different compositions tested, the 10% PVP/2% CMC-Na composite microneedle demonstrated the best performance with a regular surface morphology and relatively high thermal decomposition and melting temperatures. These results indicate that microneedles with appropriate ratios of two different materials possess good formability and other properties.

Reduction-responsive worm-like nanoparticles for synergistic cancer chemo-photodynamic therapy

Chemo-photodynamic therapy shows great potential for cancer treatment. However, the rational integration of chemotherapeutic agents and photosensitizers to construct an intelligent nanoplatform with synergistic therapeutic effect is still a great challenge. In this work, curcumin-loaded reduction-responsive prodrug nanoparticles of new indocyanine green (Cur@IR820-ss-PEG) were developed for synergistic cancer chemo-photodynamic therapy. Cur@IR820-ss-PEG exhibit high drug loading content and special worm-like morphology, contributing to their efficient cellular uptake. Due to the presence of the disulfide bond between IR820 and PEG, Cur@IR820-ss-PEG display reduction responsive drug release behaviors. The efficient cellular uptake and reduction triggered drug release of Cur@IR820-ss-PEG lead to their enhanced in vitro cytotoxicity against 4T1cells as compared to the mixture of IR820 and curcumin (IR820/Cur) under laser irradiation. Besides, Cur@IR820-ss-PEG exhibit prolonged blood half-life time, better tumor accumulation and retention, enhanced tumor hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial cell growth factor (VEGF) suppression effect as compared to IR820/Cur. In vivo antitumor activity study, Cur@IR820-ss-PEG effectively inhibit the tumor angiogenesis, which potentiates the PDT efficacy and leads to the best in vivo antitumor effect of Cur@IR820-ss-PEG. This work provides a novel and relatively simple strategy for synergistic cancer chemo-photodynamic therapy.

"NIR-triggered ROS storage" photodynamic intraocular implant for high-efficient and safe posterior capsular opacification prevention

Posterior capsular opacification (PCO) is the leading cause of vision loss after cataract, mainly caused by the adhesion, proliferation and trans-differentiation of post-operative residual lens epithelial cells (LECs). Effective PCO prevention remains a huge challenge to ophthalmologists and researches for decades. Herein, we developed a "NIR-triggered ROS storage" intraocular implant (CTR-Py-PpIX) based on capsular tension ring (CTR), which is concurrently linked with photosensitizer protophorphyrin IX (PpIX) and energy storage 2-pyridone derivative (Py), to guarantee instantaneous and sustainable ROS generation for LECs killing, aiming to achieve more efficient and safer photodynamic therapy (PDT) to effectively prevent PCO. The silylated PpIX-Si and Py-Si were covalently conjugated to the plasma activated CTR surface to obtain CTR-Py-PpIX. Results demonstrated that CTR-Py-PpIX had dual functions of PDT and battery, in which PpIX could generate ROS extracellularly under irradiation, with one part directly inhibiting LECs by lipid peroxidation (LPO) induction of cell membranes. Meanwhile, the excess ROS stored in Py could be continuously released to amplify LPO levels after the irradiation was removed. Ultimately, the proliferation of LECs in capsular bag was completely inhibited under mild irradiation conditions, achieving a sustainable and controlled PDT effect for effective PCO prevention with good biocompatibility. This NIR-triggered ROS storage intraocular implant would provide a more efficient and safer approach for long-term PCO prevention.