Interplay between G protein-coupled receptors and nanotechnology

Nano-polymeric platinum activates PAR2 gene editing to suppress tumor metastasis

Metastasis as the hallmark of cancer preferentially contributes to tumor recurrence and therapy resistance, aggrandizing the lethality of patients with cancer. Despite their robust suppressions of tumor progression, chemotherapeutics failed to attenuate cancer cell migration and even triggered pro-metastatic effects. In parallel, protease-activated receptor 2 (PAR2), a member of the G protein-coupled receptor subfamily, actively participates in cancer metastasis via multiple signal transduction pathways. CRISPR/Cas9 that is a dominating genome editing tool can evoke PAR2 knockout to inhibit cancer metastasis. However, the absence of valid delivery systems largely limits its efficacy. Herein, we nanosized polymeric platinum (NanoPt) as therapeutical drug carries to deliver CRISPR/Cas9 to elicit genome editing of PAR2, which drastically augmented anti-metastatic effects and alleviated systematic toxicity of platinum-based treatment in vitro and in vivo. More importantly, the NanoPt@Cas9-PAR2 initiated PAR2 deficiency to mechanistically attenuate EMT process and ferroptosis via RAGE/ERK signalling, consequently preventing cancer cell migration. Our findings indicate that NanoPt@Cas9-PAR2 that mitigated PAR2 signalling and cytotoxic effects of platinum could be a safe and powerful all-in-one combinatorial strategy for cancer treatment.

Nanoodor Particles Deliver Drugs to Central Nervous System via Olfactory Pathway

Central nervous system (CNS) disorders confront significant challenges in drug delivery due to the blood-brain barrier (BBB). Inspired by the rapid and precise binding of odor molecules to olfactory receptors (ORs), this research uses thiolated HPMA to construct odor nanoparticles (nanoodors) capable of delivering drugs to the CNS via the olfacto-cerebral pathway to overcome the delivery obstruction. The nanoodor core is used to encapsulate agomelatine (AGO), a CNS-targeting antidepressant, and the encapsulation efficiency exceeded 80%. A series of thiol-presenting nanoscale structures with different surface densities of thiol groups are constructed, and the effectiveness positively correlated with the density of thiol groups on their surface. Notably, the nanoodors enable precise brain-targeted delivery, outperforming commercially available oral formulations in terms of drug accumulation in the brain and antidepressant effects. The study of the nanoodor transport and action mechanisms revealed that after binding to ORs, the nanoodors are rapidly delivered to the brain via the olfactory pathway. Nanoodors, the first design to deliver CNS drugs via the olfactory pathway by mimicking natural smells for the treatment of CNS disorders, are expected to achieve clinical transformation, benefiting human health.

Active targeting of type 1 diabetes therapies to pancreatic beta cells using nanocarriers

Type 1 diabetes is an autoimmune disease characterised by the destruction of pancreatic beta cells, resulting in lifelong insulin dependence. Although exogenous insulin can maintain glycaemic control, this approach does not protect residual or replacement pancreatic beta cells from immune-mediated death. Current therapeutics designed to protect functional beta cell mass or promote beta cell proliferation and regeneration can have off-target effects, resulting in higher dose requirements and adverse side effects. Targeted drug delivery using nanocarriers has demonstrated potential for overcoming these limitations. The critical bottleneck limiting the development of beta cell-targeted therapies is a lack of highly specific beta cell markers. This review provides an overview of the use of nanocarriers for cell-targeted delivery and the current state of the field of beta cell targeting. Technologies such as systematic evolution of ligands by exponential enrichment (SELEX) aptamer selection, phage display screening, and omics datasets from human samples are highlighted as tools to identify novel beta cell-specific targets that can be combined with nanocarriers for targeted delivery of therapeutics. Ultimately, beta cell-targeted therapies using nanocarriers present a unique opportunity to develop tailored treatments for each stage of type 1 diabetes with the goal of providing individuals with treatment options that prevent further progression or reverse the course of the disease.

PLGA confers upon conventional nonfluorescent molecules luminescent properties to trigger 1O2-induced pyroptosis and immune response in tumors

Pyroptosis, a recently identified cellular demise regulated by gasdermin family proteins, is emerging as a promising avenue in cancer immunotherapy. However, the realm of light-controlled pyroptosis in cancer cells remains largely unexplored. In this study, we took a deliberate approach devoid of any chemical alterations to develop a novel photosensitizer called "pharmaceutical-dots (pharm-dots)" by combining nonemissive polymers (Poly (lactic-co-glycolic acid), PLGA) with nonfluorescent invisible molecules like curcumin, berberine, oridonin into PLGA nanoparticles (PLGA-NPs). Initially, our research commenced with a comprehensive mechanistic comparison study, consolidating fragmented information on optical mechanisms. This exploration revealed that surface passivation atoms play a dominant role in governing the fluorescence emission of PLGA-NPs. Remarkably, these new luminophores, composed of two non-inherently luminous components, exhibit a remarkable synergistic boost in photoluminescence through a "0 + 0 > 2" phenomenon. In-depth investigations uncovered that these luminous PLGA-NPs, capable of generating 1O2, induce pyroptosis under photoexcitation conditions through the caspase-3/gasdermin E (GSDME) pathway. Simultaneously, our findings highlight PLGA-NPs as a novel optical formulation suitable for imaging, displaying substantial biological activity when paired with photoirradiation. This discovery holds the potential to facilitate the application of light-controlled pyroptosis in antitumor therapy, marking a promising stride toward innovative approaches in cancer treatment.

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

Low-Dose Trypsin Accelerates Wound Healing via Protease-Activated Receptor 2

The management of wounds remains a significant healthcare challenge, highlighting the need for effective wound healing strategies. To address this, it is crucial to explore the molecular mechanisms underlying tissue repair as well as explore potential therapeutic approaches. Trypsin, as a serine protease, has been clinically utilized for wound healing for decades; however, it still lacks systemic investigation on its role and related mechanism. This study aimed to investigate the effects of low-dose trypsin on wound healing both in vitro and in vivo. While trypsin is an endogenous stimulus for protease-activated receptor 2 (PAR2), we discovered that both low-dose trypsin and synthesized PAR2 agonists significantly enhanced the migration, adhesion, and proliferation of fibroblasts and macrophages, similar to the natural repair mechanism mediated by mast cell tryptase. Moreover, such cell functions induced by trypsin were largely inhibited by PAR2 blockade, indicating the participation of trypsin via PAR2 activation. Additionally, low-dose trypsin notably expedited healing and regeneration while enhancing collagen deposition in skin wounds in vivo. Importantly, upon stimulation of trypsin or PAR2 agonists, there were significant upregulations of genes including claudin-7 (Cldn7), occludin (Ocln), and interleukin-17A (IL-17A) associated with proliferation and migration, extracellular matrix (ECM), tight junction, and focal adhesion, which contributed to wound healing. In summary, our study suggested that a low-dose trypsin could be a promising strategy for wound healing, and its function was highly dependent on PAR2 activation.