Tumor localization of oncolytic adenovirus assisted by pH-degradable microgels with JQ1-mediated boosting replication and PD-L1 suppression for enhanced cancer therapy

Gelatin methacryloyl granular scaffolds for localized mRNA delivery

mRNA therapy is the intracellular delivery of messenger RNA (mRNA) to produce desired therapeutic proteins. Developing strategies for local mRNA delivery is still required where direct intra-articular injections are inappropriate for targeting a specific tissue. The mRNA delivery efficiency depends on protecting nucleic acids against nuclease-mediated degradation and safe site-specific intracellular delivery. Herein, we report novel mRNA-releasing matrices based on RGD-moiety-rich gelatin methacryloyl (GelMA) microporous annealed particle (MAP) scaffolds. GelMA concentration in aerogel-based microgels (μgels) produced through a microfluidic process, MAP stiffnesses, and microporosity are crucial parameters for cell adhesion, spreading, and proliferation. After being loaded with mRNA complexes, MAP scaffolds composed of 10 % GelMA μgels display excellent cell viability with increasing cell infiltration, adhesion, proliferation, and gene transfer. The intracellular delivery is achieved by the sustained release of mRNA complexes from MAP scaffolds and cell adhesion on mRNA-releasing scaffolds. These findings highlight that hybrid systems can achieve efficient protein expression by delivering mRNA complexes, making them promising mRNA-releasing biomaterials for tissue engineering.

Recent advances in microfluidic-based cancer immunotherapy-on-a-chip strategies

Despite several extraordinary improvements in cancer immunotherapy, its therapeutic effectiveness against many distinct cancer types remains mostly limited and requires further study. Different microfluidic-based cancer immunotherapy-on-a-chip (ITOC) systems have been developed to help researchers replicate the tumor microenvironment and immune system. Numerous microfluidic platforms can potentially be used to perform various on-chip activities related to early clinical cancer immunotherapy processes, such as improving immune checkpoint blockade therapy, studying immune cell dynamics, evaluating cytotoxicity, and creating vaccines or organoid models from patient samples. In this review, we summarize the most recent advancements in the development of various microfluidic-based ITOC devices for cancer treatment niches and present future perspectives on microfluidic devices for immunotherapy research.

Lung cancer and oncolytic virotherapy--enemy's enemy

Lung cancer is one of the malignant tumors that seriously threaten human health worldwide, while the covid-19 virus has become people's nightmare after the coronavirus pandemic. There are too many similarities between cancer cells and viruses, one of the most significant is that both of them are our enemies. The strategy to take the advantage of the virus to beat cancer cells is called Oncolytic virotherapy. When immunotherapy represented by immune checkpoint inhibitors has made remarkable breakthroughs in the clinical practice of lung cancer, the induction of antitumor immunity from immune cells gradually becomes a rapidly developing and promising strategy of cancer therapy. Oncolytic virotherapy is based on the same mechanisms that selectively kill tumor cells and induce systemic anti-tumor immunity, but still has a long way to go before it becomes a standard treatment for lung cancer. This article provides a comprehensive review of the latest progress in oncolytic virotherapy for lung cancer, including the specific mechanism of oncolytic virus therapy and the main types of oncolytic viruses, and the combination of oncolytic virotherapy and existing standard treatments. It aims to provide new insights and ideas on oncolytic virotherapy for lung cancer.

Distinguishing the Pros and Cons of Metabolic Reprogramming in Oncolytic Virus Immunotherapy

Oncolytic viruses (OVs) represent a class of cancer immunotherapies that rely on hijacking the host cell factory for replicative oncolysis and eliciting immune responses for tumor clearance. An increasing evidence suggests that the metabolic state of tumor cells and immune cells is a putative determinant of the efficacy of cancer immunotherapy. However, how therapeutic intervention with OVs affects metabolic fluxes within the tumor microenvironment (TME) remains poorly understood. Herein, we review the complexities of metabolic reprogramming involving the effects of viruses and their consequences on tumor cells and immune cells. We highlight the inherent drawback of oncolytic virotherapy, namely that treatment with OVs inevitably further exacerbates the depletion of nutrients and the accumulation of metabolic wastes in the TME, leading to a metabolic barrier to antitumor immune responses. We also describe targeted metabolic strategies that can be used to unlock the therapeutic potential of OVs.

Translating Therapeutic Microgels into Clinical Applications

Microgels are crosslinked, water-swollen networks with a 10 nm to 100 µm diameter and can be modified chemically or biologically to render them biocompatible for advanced clinical applications. Depending on their intended use, microgels require different mechanical and structural properties, which can be engineered on demand by altering the biochemical composition, crosslink density of the polymer network, and the fabrication method. Here, the fundamental aspects of microgel research and development, as well as their specific applications for theranostics and therapy in the clinic, are discussed. A detailed overview of microgel fabrication techniques with regards to their intended clinical application is presented, while focusing on how microgels can be employed as local drug delivery materials, scavengers, and contrast agents. Moreover, microgels can act as scaffolds for tissue engineering and regeneration application. Finally, an overview of microgels is given, which already made it into pre-clinical and clinical trials, while future challenges and chances are discussed. This review presents an instructive guideline for chemists, material scientists, and researchers in the biomedical field to introduce them to the fundamental physicochemical properties of microgels and guide them from fabrication methods via characterization techniques and functionalization of microgels toward specific applications in the clinic.

iRGD Tumor-Penetrating Peptide-Modified Nano-Delivery System Based on a Marine Sulfated Polysaccharide for Enhanced Anti-Tumor Efficiency Against Breast Cancer

Background

Breast cancer is a common malignancy in women. Conventional clinical therapies for breast cancer all display moderate clinical efficacies and limitations. It is urgent to explore the novel and combined therapeutic strategies for breast cancer to meet clinical demand.

Methods

An iRGD tumor-penetrating peptide-modified nano-delivery system (denoted as iRGD-PSS@PBAE@JQ1/ORI nanoparticles) based on a marine sulfated polysaccharide was developed by codelivery of JQ1 (BET inhibitor) and oridonin (ORI, bioactive diterpenoid derived from traditional Chinese medicine herb). The iRGD-PSS@PBAE@JQ1/ORI NPs, surface modified with iRGD peptide conjugated propylene glycol alginate sodium sulfate (iRGD-PSS). The antitumor efficacy was evaluated both in vitro and in vivo.

Results

The prepared iRGD-PSS@PBAE@JQ1/ORI NPs effectively enhanced the tumor targeting and cellular internalization of JQ1 and ORI. Thus, JQ1 exerted the reversal effect on immune tolerance by decreasing the expression of PD-L1, while ORI displayed multiple antitumor effects, such as antiproliferation, inhibition of intracellular ROS production and inhibition of lactic acid secretion.

Conclusion

Our data revealed that iRGD peptide could significantly improve the cellular internalization and tumor penetration of the nano-delivery system. The combination of JQ1 and ORI could exert synergistic antitumor activities. Taken together, this study provides a multifunctional nanotherapeutic system to enhance the anti-tumor efficiency against breast cancer.

Application of Microfluidic Systems for Breast Cancer Research

Cancer is a disease in which cells in the body grow out of control; breast cancer is the most common cancer in women in the United States. Due to early screening and advancements in therapeutic interventions, deaths from breast cancer have declined over time, although breast cancer remains the second leading cause of cancer death among women. Most deaths are due to metastasis, as cancer cells from the primary tumor in the breast form secondary tumors in remote sites in distant organs. Over many years, the basic biological mechanisms of breast cancer initiation and progression, as well as the subsequent metastatic cascade, have been studied using cell cultures and animal models. These models, although extremely useful for delineating cellular mechanisms, are poor predictors of physiological responses, primarily due to lack of proper microenvironments. In the last decade, microfluidics has emerged as a technology that could lead to a paradigm shift in breast cancer research. With the introduction of the organ-on-a-chip concept, microfluidic-based systems have been developed to reconstitute the dominant functions of several organs. These systems enable the construction of 3D cellular co-cultures mimicking in vivo tissue-level microenvironments, including that of breast cancer. Several reviews have been presented focusing on breast cancer formation, growth and metastasis, including invasion, intravasation, and extravasation. In this review, realizing that breast cancer can recur decades following post-treatment disease-free survival, we expand the discussion to account for microfluidic applications in the important areas of breast cancer detection, dormancy, and therapeutic development. It appears that, in the future, the role of microfluidics will only increase in the effort to eradicate breast cancer.

Enzyme-responsive micellar JQ1 induces enhanced BET protein inhibition and immunotherapy of malignant tumors

Bromodomain and extra-terminal (BET) proteins are attractive targets for treating various malignancies including melanoma. The inhibition of BET bromodomains, e.g. with JQ1, is found to downregulate the expression of both c-MYC oncoprotein and programmed cell death ligand 1 (PD-L1), which play a crucial role in tumor growth and the immunosuppressive tumor microenvironment, respectively. The BET bromodomain inhibitors like JQ1 though exhibiting high selectivity and affinity show usually low bioavailability and efficacy in vivo due to fast clearance and inferior uptake by tumor cells. The therapeutic effect of JQ1 might further be lowered by drug resistance. Here, enzyme-responsive micellar JQ1 (mJQ1) was fabricated from a poly(ethylene glycol)-b-poly(L-tyrosine) copolypeptide to enhance JQ1 delivery and the immunotherapy of malignant melanoma. The in vitro results showed that mJQ1 induced clearly better repression of c-MYC and PD-L1 proteins, cell cycle arrest, cell inhibition, and apoptotic activity than free JQ1 in B16F10 cancer cells. The intratumoral administration of mJQ1 at 2.5 mg of JQ1 equiv. per kg was found to show better inhibition of B16F10 tumors in C57BL/6 mice than the intraperitoneal administration of free JQ1 at 50 mg kg^-1. In particular, when combined with radiotherapy, mJQ1 effectively suppressed tumor growth and brought about strong local and systemic antitumor immunity as evidenced by elevated CD8+ T cells and increased ratios of CD8+ T cells to Tregs, affording significantly improved survival of B16F10 tumor-bearing mice than their JQ1 counterparts and marked growth suppression of distant tumors. The great potency of enzyme-responsive micellar JQ1 makes it interesting for immunotherapy of various tumors.

Spontaneously Self-Assembled Microgel Film as Co-Delivery System for Skincare Applications

Nowadays, the design of innovative delivery systems is driving new product developments in the field of skincare. In this regard, serving as potential candidates for on-demand drug delivery and fulfilling advanced mechanical and optical properties together with surface protection, spontaneously self-assembled microgel films can be proposed as ideal smart skincare systems. Currently, the high encapsulation of more than one drug simultaneously in a film is a very challenging task. Herein, different ratios (1:1, 3:1, 9:1) of different mixtures of hydrophilic/hydrophobic UVA/UVB-absorbers working together in synergy and used for skin protection were encapsulated efficiently into spontaneously self-assembled microgel films. In addition, in vitro release profiles show a controlled release of the different active molecules regulated by the pH and temperature of the medium. The analysis of the release mechanisms by the Peppas-Sahlin model indicated a superposition of diffusion-controlled and swelling-controlled releases. Finally, the distribution of active molecule mixtures into the film was studied by confocal Raman microscopy imaging corroborating the release profiles obtained.

The BET family in immunity and disease

Innate immunity serves as the rapid and first-line defense against invading pathogens, and this process can be regulated at various levels, including epigenetic mechanisms. The bromodomain and extraterminal domain (BET) family of proteins consists of four conserved mammalian members (BRD2, BRD3, BRD4, and BRDT) that regulate the expression of many immunity-associated genes and pathways. In particular, in response to infection and sterile inflammation, abnormally expressed or dysfunctional BETs are involved in the activation of pattern recognition receptor (e.g., TLR, NLR, and CGAS) pathways, thereby linking chromatin machinery to innate immunity under disease or pathological conditions. Mechanistically, the BET family controls the transcription of a wide range of proinflammatory and immunoregulatory genes by recognizing acetylated histones (mainly H3 and H4) and recruiting transcription factors (e.g., RELA) and transcription elongation complex (e.g., P-TEFb) to the chromatin, thereby promoting the phosphorylation of RNA polymerase II and subsequent transcription initiation and elongation. This review covers the accumulating data about the roles of the BET family in innate immunity, and discusses the attractive prospect of manipulating the BET family as a new treatment for disease.

Materials promoting viral gene delivery

Therapeutic viral gene delivery is an emerging technology which aims to correct genetic mutations by introducing new genetic information to cells either to correct a faulty gene or to initiate cell death in oncolytic treatments. In recent years, significant scientific progress has led to several clinical trials resulting in the approval of gene therapies for human treatment. However, successful therapies remain limited due to a number of challenges such as inefficient cell uptake, low transduction efficiency (TE), limited tropism, liver toxicity and immune response. To adress these issues and increase the number of available therapies, additives from a broad range of materials like polymers, peptides, lipids, nanoparticles, and small molecules have been applied so far. The scope of this review is to highlight these selected delivery systems from a materials perspective.

Biosilicified oncolytic adenovirus for cancer viral gene therapy

Oncolytic adenoviruses (OAs) have shown great potential for cancer viral gene therapy in clinical studies. To date, clinical trials have shown that the curative efficacy of OAs is still limited by hepatic sequestration and preexisting neutralizing antibodies (nAbs), which decrease the accumulation of the OAs in tumors. Herein, with the biosilicification method, we encapsulated an OA encoding the anticancer gene Trail (OA-Trail) with silica, which significantly improved virus distribution and tumor inhibition. In vitro and in vivo results indicated that compared with the native OA, biosilicified OA-Trail (OA-Trail@SiO₂) showed significantly reduced viral clearance in the liver and evaded nAb degradation, inducing an efficacious anticancer effect under the premise of biocompatibility. These achievements present an alternative strategy involving biosilicification for enhanced OA-based cancer gene therapy.