Nano-PROTACs: state of the art and perspectives.

PROteolysis TArgeting Chimeras (PROTACs), as a recently identified technique in the field of new drug development, provide new concepts for disease treatment and are expected to revolutionize drug discovery. With high specificity and flexibility, PROTACs serve as an innovative research tool to target and degrade disease-relevant proteins that are not currently pharmaceutically vulnerable to eliminating their functions by hijacking the ubiquitin-proteasome system. To date, PROTACs still face the challenges of low solubility, poor permeability, off-target effects, and metabolic instability. The combination of nanotechnology and PROTACs has been explored to enhance the in vivo performance of PROTACs regarding overcoming these challenging hurdles. In this review, we summarize the latest advancements in the building-block design of PROTAC prodrug nanoparticles and provide an overview of existing/potential delivery systems and loading approaches for PROTAC drugs. Furthermore, we discuss the current status and prospects of the split-and-mix approach for PROTAC drug optimization. Additionally, the advantages and translational potentials of carrier-free nano-PROTACs and their combinational therapeutic effects are highlighted. This review aims to foster a deeper understanding of this rapidly evolving field and facilitate the progress of nano-PROTACs that will continue to push the boundaries of achieving selectivity and controlled release of PROTAC drugs.

Biomimetic nanomedicines for precise atherosclerosis theranostics.

Atherosclerosis (AS) is a leading cause of the life-threatening cardiovascular disease (CVD), creating an urgent need for efficient, biocompatible therapeutics for diagnosis and treatment. Biomimetic nanomedicines (bNMs) are moving closer to fulfilling this need, pushing back the frontier of nano-based drug delivery systems design. This review seeks to outline how these nanomedicines (NMs) might work to diagnose and treat atherosclerosis, to trace the trajectory of their development to date and in the coming years, and to provide a foundation for further discussion about atherosclerotic theranostics.

Conformation Dependent Architectures of Assembled Antimicrobial Peptides with Enhanced Antimicrobial Ability.

Antimicrobial peptides (AMPs) are a developing class of natural and synthetic oligopeptides with host defense mechanisms against a broad spectrum of microorganisms. With in-depth research on the structural conformations of AMPs, synthesis or modification of peptides has shown great potential in effectively obtaining new therapeutic agents with improved physicochemical and biological properties. Notably, AMPs with self-assembled properties have gradually become a hot research topic for various biomedical applications. Compared to monomeric peptides, these peptides can exist in diverse forms (e.g., nanoparticles, nanorods, and nanofibers) and possess several advantages, such as high stability, good biocompatibility, and potent biological functions, after forming aggregates under specific conditions. In particular, the stability and antibacterial property of these AMPs can be modulated by rationally regulating the peptide sequences to promote self-assembly, leading to the reconstruction of molecular structure and spatial orientation while introducing some peptide fragments into the scaffolds. In this work, four self-assembled AMPs are developed, and the relationship between their chemical structures and antibacterial activity is explored extensively through different experiments. Importantly, the evaluation of antibacterial performance in both in vitro and in vivo studies has provided a general guide for using self-assembled AMPs in subsequent treatments for combating bacterial infections.

The effect of drug holiday on preventing medication-related osteonecrosis of the jaw in osteoporotic rat model.

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication associated with antiresorptive medications managing osteoporosis, such as bisphosphonates (BPs). To date, there is very limited evidence from prospective, controlled studies to support or refute the controversial prevention regimen that if a discontinuation of BPs before dentoalveolar surgery, so called "drug holiday", is effective in reducing the risk of MRONJ development in patients with osteoporosis. We proposed an experimental animal study, aiming to investigate the prevention of MRONJ following tooth extractions in osteoporotic condition, with the implementation of a BP drug holiday. Methods: Twenty rats were subjected to bilateral ovariectomy. After establishing the osteoporotic condition, all rats were exposed to weekly injections of zoledronate acid (ZA) for 8 weeks. After ZA treatment, 10 rats were subjected to dental extraction and defined as control group, and the rest 10 rats assigned to the DH group had a drug holiday of 8 weeks prior to dental extraction. Eight weeks after the dentoalveolar surgery, bone turnover biomarker in serum, occurrence of MRONJ-like lesion and histomorphometric assessment of osteonecrosis in mandible, and bone microarchitecture indices in femur, were examined. Results: Eight weeks after dental extraction, the DH group showed a recovered osteoclastic activity, indicated by significantly increased number of osteoclasts in the mandibles and serum level of C-terminal telopeptides of type I collagen, as compared to the control group. No significant differences were observed in the gross-view and histological occurrences of MRONJ-like lesions between the two groups.There was no significant difference in bone microarchitecture in the femur between the control and DH groups before ZA therapy and 8 weeks after dental extraction. Conclusion: Our data provided the first experimental evidence in the osteoporotic animal model that the implementation of a BP holiday in prior to dental extractions could partially recover osteoclastic activity, but could not alleviate the development of MRONJ-like lesion or exacerbate the osteoporotic condition in the femur. Longer-term drug holiday, or combination of drug holiday and other prophylaxes to prevent MRONJ in patients with osteoporosis could be worth exploring in future studies, to pave the way for clinical managements. The translational potential of this article: This in vivo prospective study reported that a recovery of osteoclastic activity by a BP drug holiday for 8 weeks in osteoporosis rats did not alleviate the development of MRONJ-like lesion followed by dental extractions. It contributes to the understanding of regimens to prevent MRONJ.

Rapid synthesis of bismuth-organic frameworks as selective antimicrobial materials against microbial biofilms.

Antibiotic resistance is a global public health threat, and urgent actions should be undertaken for developing alternative antimicrobial strategies and approaches. Notably, bismuth drugs exhibit potent antimicrobial effects on various pathogens and promising efficacy in tackling SARS-CoV-2 and related infections. As such, bismuth-based materials could precisely combat pathogenic bacteria and effectively treat the resultant infections and inflammatory diseases through a controlled release of Bi ions for targeted drug delivery. Currently, it is a great challenge to rapidly and massively manufacture bismuth-based particles, and yet there are no reports on effectively constructing such porous antimicrobial-loaded particles. Herein, we have developed two rapid approaches (i.e., ultrasound-assisted and agitation-free methods) to synthesizing bismuth-based materials with ellipsoid- (Ellipsoids) and rod-like (Rods) morphologies respectively, and fully characterized physicochemical properties. Rods with a porous structure were confirmed as bismuth metal-organic frameworks (Bi-MOF) and aligned with the crystalline structure of CAU-17. Importantly, the formation of Rods was a 'two-step' crystallization process of growing almond-flake-like units followed by stacking into the rod-like structure. The size of Bi-MOF was precisely controlled from micro-to nano-scales by varying concentrations of metal ions and their ratio to the ligand. Moreover, both Ellipsoids and Rods showed excellent biocompatibility with human gingival fibroblasts and potent antimicrobial effects on the Gram-negative oral pathogens including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Both Ellipsoids and Rods at 50 â€‹µg/mL could disrupt the bacterial membranes, and particularly eliminate P. gingivalis biofilms. This study demonstrates highly efficient and facile approaches to synthesizing bismuth-based particles. Our work could enrich the administration modalities of metallic drugs for promising antibiotic-free healthcare.

Bone-Targeted Dual Functional Lipid-coated Drug Delivery System for Osteosarcoma Therapy.

PURPOSE OR OBJECTIVE: Osteosarcoma is well-known for its high incidence in children and adolescents and long-term bone pain, which seriously reduces the life quality of patients. Cisplatin (CDDP), as the first-line anti-osteosarcoma drug, has been used in many anticancer treatments. At the same time, the serious side effects of platinum (Pt) drugs have also attracted widespread attention. To accurately deliver Pt drugs to the lesion site and realize controlled release of Pt drugs, certain modified delivery systems have been extensively studied. METHODS: Among them, liposomes have been approved for clinical cancer treatment due to their highly biocompatibility and superior modifiability. Here, we developed a bone-targeted dual functional lipid-coated drug delivery system, lipid-coated CDDP alendronate nanoparticles (LCA NPs) to target the bone and precisely deliver the drugs to the tumor site. Cell toxicity, apoptosis and cellular uptake were detected to evaluate the anticancer effect for LCA NPs. Furthermore, transwell assay and wound healing assay were conducted to estimate the osteosarcoma cell migration and invasion. Hemolysis assay was utilized to assess the biocapitibility of the kind of NPs. RESULTS: With the aim of bone-targeted unit alendronate (ALD), LCA NPs serve as a rich bone homing Pt delivery system to exert efficient anticancer effects and synergistically reduce bone resorption and bone loss potentially. CONCLUSIONS: By providing a highly biocompatible platform for osteosarcoma therapy, LCA NPs may help to significantly enhance the anticancer effect of Pt and greatly reduce the systemic toxicity and side effects of Pt towards osteosarcoma.

Navigations of the targeting pathway of nanomedicines toward tumor.

INTRODUCTION: Nanomedicines (NMs) have emerged as a promising approach for revolutionizing cancer treatment outcomes, mainly due to their benefits in the tumor-targeted delivery of therapeutics. The preferential accumulation of NMs in tumors has been widely verified by macroscopical technologies. Accordingly, several classic and emerging targeting mechanisms have been proposed to support the tumor-specific delivery of NMs. The targeting mechanism has been a topic of intense interest and controversy in the field of NMs development. Especially, the mechanisms by which NMs target tumor remain elusive. AREA COVERED: This topical review mainly discussed the evolution of the targeting mechanisms, crucial issues associated with each mechanism, and confused debates among the mechanisms. The targeting mechanisms of tumor-specific NMs discussed here include the enhanced permeability and retention (EPR) effect, protein corona-mediated targeting delivery, circulating cell mediated transportation, and transcytosis. EXPERT OPINION: It is of great significance for ultimate clinical translation to have more comprehensive considerations on the mechanism driving the pathway of NMs toward tumors. Our thoughts in this review are expected to provide a comprehensive understanding of the mechanisms and elicit thorough explorations of new mechanisms to renovate the knowledge framework of NMs delivery. [Figure: see text].

Imaging-guided/improved diseases management for immune-strategies and beyond.

Timely and accurate assessment and diagnosis are extremely important and beneficial for all diseases, especially for some of the major human disease, such as cancers, cardiovascular diseases, infectious diseases, and neurodegenerative diseases. Limited by the variable disease microenvironment, early imperceptible symptoms, complex immune system interactions, and delayed clinical phenotypes, disease diagnosis and treatment are difficult in most cases. Molecular imaging (MI) techniques can track therapeutic drugs and disease sites in vivo and in vitro in a non-invasive, real-time and visible strategies. Comprehensive visual imaging and quantitative analysis based on different levels can help to clarify the disease process, pathogenesis, drug pharmacokinetics, and further evaluate the therapeutic effects. This review summarizes the application of different MI techniques in the diagnosis and treatment of these major human diseases. It is hoped to shed a light on the development of related technologies and fields.

Biodegradable magnesium implant enhances angiogenesis and alleviates medication-related osteonecrosis of the jaw in rats.

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a serious complication associated with antiresorptive and antiangiogenic medications, of which impaired angiogenesis is a key pathological alteration. Since Magnesium (Mg)-based implants possess proangiogenic effects, we hypothesized that the biodegradable Mg implant could alleviate the development of MRONJ via enhancing angiogenesis. Methods: MRONJ model was established and divided into the Veh â€‹+ â€‹Ti group (Vehicle-treated rat, with Titanium (Ti) implant), BP â€‹+ â€‹Ti group (Bisphosphonate (BP)-treated rat, with Ti implant), BP â€‹+ â€‹Mg group (BP-treated rat, with Mg implant), BP â€‹+ â€‹Mg â€‹+ â€‹SU5416 group (BP-treated rat, with Mg implant and vascular endothelial growth factor (VEGF) receptor-2 inhibitor), BP â€‹+ â€‹Mg â€‹+ â€‹BIBN group (BP-treated rat, with Mg implant and calcitonin gene-related peptide (CGRP) receptor antagonist), and BP â€‹+ â€‹Mg â€‹+ â€‹SU5416+BIBN group (BP-treated rat, with Mg implant and VEGF receptor-2 inhibitor and CGRP receptor antagonist). The occurrence of MRONJ, alveolar bone necrosis, new bone formation and vessel formation were assessed by histomorphometry, immunohistochemistry, and micro-CT analysis. Results: Eight weeks after surgery, the BP â€‹+ â€‹Mg group had significantly reduced occurrence of MRONJ-like lesion and histological osteonecrosis, increased bone microstructural parameters, and increased expressions of VEGFA and CGRP, than the BP â€‹+ â€‹Ti group. By simultaneously blocking VEGF receptor-2 and CGRP receptor, the vessel volume and new bone formation in the BP â€‹+ â€‹Mg group were significantly decreased, meanwhile the occurrence of MRONJ-like lesion and histological bone necrosis were significantly increased. Conclusion: Biodegradable Mg implant could alleviate the development of MRONJ-like lesion, possibly via upregulating VEGF- and CGRP-mediated angiogenesis. Mg-based implants have the translational potential to be developed as a novel internal fixation device for patients with the risk of MRONJ. The Translational potential of this article: This work reports a biodegradable Mg implant which ameliorates the development of MRONJ-like lesions possibly due to its angiogenic property. Mg-based implants have the potential to be developed as a novel internal fixation device for patients at the risk of MRONJ.

Dual Drug Loaded pH-sensitive Micelles for Efficient Bacterial Infection Treatment.

PURPOSE: Methicillin-resistant Staphylococcus aureus (MRSA) infection at impaired wound is associated with high risks of developing to persistent bacterial infections since bacterial biofilm is easy to form in MRSA infected wounds. An advanced therapeutic approach to effectively penetrate and eliminate bacterial biofilm and to accelerate cell proliferation and migration at the wound is crucial. METHODS: The poly(ε-caprolactone)-monomethoxyl poly (ethylene glycol) (PCL-mPEG) micelles loaded with Quercetin and Rifampicin (QRMs) were prepared. Bacterial biofilm proliferation and elimination effect of QRMs were evaluated with confocal laser scanning microscopy. Antibacterial assay was further performed to detect antibacterial activity and mechanism. The cell scratch assay and cellular uptake were performed in HaCaT skin epithelial cells. RESULTS: Our results showed that the small sized QRMs could penetrate the interior of MRSA biofilm to disperse and eradicate biofilm. Then, antibiotics are released and accumulated in the acidic biofilm environment. QRMs could kill bacteria through increasing bacterial membrane permeability and altering membrane potential and membrane fluidity. Moreover, QRMs improved intracellular and cytoplasmic delivery efficiency of drugs to epithelial cells, and in the scratch test, presented a stronger ability to promote migration and proliferation of HaCaT cells compared with free drugs. Hemolysis test further proved good biocompatibility of QRMs. CONCLUSIONS: QRMs could potentially be used as a novel dual-functional nanotherapeutic for anti-bacterial infection by eradicating biofilm and accelerating cells proliferation at MRSA infected wound.

Microneedles loaded with anti-PD-1-cisplatin nanoparticles for synergistic cancer immuno-chemotherapy.

Programmed cell death protein-1 (PD-1) on T-cells combined with programmed cell death ligand-1 (PD-L1) critically accounts for tumor immune evasion. Anti-PD-1 (aPD-1) blocks the binding of PD-1 to PD-L1, thus allowing T-cell activation for tumor cell eradication. Currently, the major challenges for cancer immunotherapy are how to improve the response rate and overcome drug resistance. Dermal administration turns out to be a promising route for immunotherapy since skin is a highly active immune organ containing a large population of resident antigen-presenting cells. Microneedle arrays can pierce the immune-cell-rich epidermis, leading to a robust T-cell response in the microenvironment of tumor cells. Herein, we successfully developed a microneedle patch loaded with pH-responsive tumor-targeted lipid nanoparticles (NPs), which allows local delivery of aPD-1 and cisplatin (CDDP) precisely to cancer tissues for cancer therapy. For in vivo studies, aPD-1/CDDP@NPs delivered through microneedles effectively boosted the immune response, thereby a remarkable effect on tumor regression was realized. Synergistic anticancer mechanisms were therefore activated through robust microneedle-induced T-cell response, blockage of PD-1 in T-cells by aPD-1, and an increase in direct cytotoxicity of CDDP in tumor cells. Strikingly, transdermal delivery using MNs increased the response rate in the animal model unresponsive to aPD-1 systemic therapy. This exhibited promise in the treatment of immunotherapy-unresponsive cancers. Taken together, microneedle-mediated local delivery of nano-encapsulated chemotherapeutic and immunotherapeutic agents at tumor skin sites provides a novel treatment strategy and insights into cancer therapy.

Saliva electrolyte analysis and xerostomia-related quality of life in nasopharyngeal carcinoma patients following intensity-modulated radiation therapy.

BACKGROUND AND PURPOSE: Nasopharyngeal carcinoma (NPC) is one of the most common cancers in southern China and the first-line treatment is radiotherapy. Intensity-modulated radiation therapy (IMRT) can deliver high dose to cancer and low dose to normal tissue, but xerostomia is still one of the complications after IMRT. However, how the concentration of saliva electrolytes be affected by IMRT and the effects on the quality of life are still unknown. In this prospective study, 76 NPC patients were recruited from hospitals in Hong Kong to identify the change of saliva electrolytes and xerostomia-related quality of life before and after IMRT. METHODS AND MATERIALS: Saliva and questionnaire were collected before IMRT, 1 month, 3 months, 6 months and 12 months after IMRT. The concentration of saliva electrolytes was detected using inductively coupled plasma-optical emission spectroscopy (ICP-OES). RESULTS: Saliva flow rate significantly decreased after IMRT. Decrease in the mean value of pH was observed but the difference is not statistically significant. The concentrations of potassium, iodine, and calcium decreased and chloride concentration increased after IMRT, while the concentrations of sodium, magnesium, copper or zinc were kept at the same level before and after treatment. Xerostomia-related quality of life was adversely affected by IMRT, but partially recovered after 1 year. CONCLUSIONS: Our study revealed the change of saliva electrolytes and xerostomia-related quality of life in patients undergone IMRT for NPC.

Microneedle-Mediated Delivery of Lipid-Coated Cisplatin Nanoparticles for Efficient and Safe Cancer Therapy.

Cisplatin is the first-line chemotherapeutic agent, but its systemic toxicity and side effects severely limit its clinical use. We report a microneedle technique to mediate the transdermal delivery of lipid-coated cisplatin nanoparticles (LCC-NPs) for efficient and safe cancer therapy. Cisplatin was encapsulated by tumor-targeting pH-responsive lipid nanoparticles with a high loading rate of 80%, and the encapsulation substantially increased the solubility of cisplatin and enhanced its antitumor efficiency in vitro. The LCC-NPs were embedded in dissolvable microneedles, and released from the microneedles after inserting into the skin. This enabled the nanoparticles to pass the stratum corneum for safe local delivery. An in vivo study with a xenograft tumor animal model demonstrated that microneedle arrays loaded with cisplatin nanoparticles significantly increased cytotoxicity and apoptosis in cancer cells with an apoptotic index of 58.6%, resulting in significantly reduced tumor volume and weight. Moreover, serum platinum, pulmonary toxicity, hepatotoxicity, and nephrotoxicity were not detected in vivo, indicating that this technique is biosafe. The cisplatin-nanoparticle microneedle system developed in this study may offer promising opportunities in cancer therapy for enhancing antitumor effects and reducing systemic toxicity and side effects.