Biomaterial-based scaffold for in situ chemo-immunotherapy to treat poorly immunogenic tumors

Immune-modulative nano-gel-nano system for patient-favorable cancer therapy

Current cancer immunotherapies exhibit low response rates attributed to suppressive tumor immune microenvironments (TIMEs). To address these unfavorable TIMEs, supplementation with tumor-associated antigens and stimulation of immune cells at target sites are indispensable for eliciting anti-tumoral immune responses. Previous research has explored the induction of immunotherapy through multiple injections and implants; however, these approaches lack consideration for patient convenience and the implementation of finely tunable immune response control systems to mitigate the side effects of over-inflammatory responses, such as cytokine storms. In this context, we describe a patient-centric nano-gel-nano system capable of sustained generation of tumor-associated antigens and release of adjuvants. This is achieved through the specific delivery of drugs to cancer cells and antigens/adjuvants to immune cells over the long term, maintaining proper concentrations within the tumor site with a single injection. This system demonstrates local immunity against tumors with a single injection, enhances the therapeutic efficacy of immune checkpoint blockades, and induces systemic and memory T cell responses, thus minimizing systemic side effects.

Delivery Systems Developed for Treatment Combinations to Improve Adoptive Cell Therapy

Adoptive cell therapy (ACT) has shown great success in the clinic for treating hematologic malignancies. However, solid tumor treatment with ACT monotherapy is still challenging, owing to insufficient expansion and rapid exhaustion of adoptive cells, tumor antigen downregulation/loss, and dense tumor extracellular matrix. Delivery strategies for combination cell therapy have great potential to overcome these hurdles. The delivery of vaccines, immune checkpoint inhibitors, cytokines, chemotherapeutics, and photothermal reagents in combination with adoptive cells, have been shown to improve the expansion/activation, decrease exhaustion, and promote the penetration of adoptive cells in solid tumors. Moreover, the delivery of nucleic acids to engineer immune cells directly in vivo holds promise to overcome many of the hurdles associated with the complex ex vivo cell engineering strategies. Here, these research advance, as well as the opportunities and challenges for integrating delivery technologies into cell therapy s are discussed, and the outlook for these emerging areas are criticlly analyzed.

Biomaterial-Based Sustained-Release Drug Formulations for Localized Cancer Immunotherapy

Cancer immunotherapy has revolutionized clinical cancer treatments by taking advantage of the immune system to selectively and effectively target and kill cancer cells. However, clinical cancer immunotherapy treatments often have limited efficacy and/or present severe adverse effects associated primarily with their systemic administration. Localized immunotherapy has emerged to overcome these limitations by directly targeting accessible tumors via local administration, reducing potential systemic drug distribution that hampers drug efficacy and safety. Sustained-release formulations can prolong drug activity at target sites, which maximizes the benefits of localized immunotherapy to increase the therapeutic window using smaller dosages than those used for systemic injection, avoiding complications of frequent dosing. The performance of sustained-release formulations for localized cancer immunotherapy has been validated preclinically using various implantable and injectable scaffold platforms. This review introduces the sustained-release formulations developed for localized cancer immunotherapy and highlights their biomaterial-based platforms for representative classes, including inorganic scaffolds, natural hydrogels, synthetic hydrogels, and microneedle patches. The design rationale and other considerations are summarized for further development of biomaterials for the construction of optimal sustained-release formulations.

A Bimetallic Nanomodulator to Reverse Immunosuppression via Sonodynamic-Ferroptosis and Lactate Metabolism Modulation

Triple-negative breast cancer (TNBC) responds poorly to immunotherapy due to insufficient immunogenicity and highly immunosuppressive tumor microenvironment (TME). Herein, an intelligent calcium/cobalt-based nanomodulator (Ca,Co)CO3-LND-TCPP@F127-TA (abbreviated as CCLT@FT) is developed to act as a sonodynamic-ferroptosis inducer and metabolic immunoadjuvant to enhance anti-tumor immunotherapy. More details, simultaneous reactive oxygen species (ROS) generation and glutathione (GSH) depletion can be achieved due to the existence of Co2+/Co3+ redox couple in CCLT@FT. Meanwhile, mitochondrial Ca2+ overload and tetrakis(4-carboxyphenyl) porphyrin (TCPP)-mediated sonodynamic therapy (SDT) further amplify the oxidative stress and promote ferroptosis in tumor cells. More impressively, CCLT@FT can modulate lactate metabolism by doping with cobalt and loading with lonidamine (LND, an inhibitor of MCT4), thereby reversing the high-lactate immunosuppressive TME. Furthermore, the combination with immune checkpoint blockade (ICB) therapy is found to achieve superior anti-tumor immunity, which in turn promotes ferroptosis of tumor cells by downregulating SLC7A11 protein, ultimately creating a "cycle" therapy. Overall, this work demonstrates a novel strategy for enhancing anti-tumor immunotherapy based on a closed-loop enhancement therapeutic route between CCLT@FT inducing ferroptosis/lactate metabolism modulation and ICB therapy, providing an alternative and important reference for effective immunotherapy of TNBC.

Multi-Metallic Nanosheets Reshaping Immunosuppressive Tumor Microenvironment through Augmenting cGAS-STING Innate Activation and Adaptive Immune Responses for Cancer Immunotherapy

The highly immunosuppressive tumor microenvironment (TME) restricts the efficient activation of immune responses. To restore the surveillance of the immune system for robust activation, vast efforts are devoted to normalizing the TME. Here, a manganese-doped layered double hydroxide (Mn-LDH) is developed for potent anti-tumor immunity by reversing TME. Mn-LDH is synthesized via a one-step hydrothermal method. In addition to the inherent proton neutralization capacity of LDH, the introduction of manganese oxide endows LDH with an additional ability to produce oxygen. Mn-LDH effectively releases Mn2+ and Mg2+ upon exposure to TME with high levels of H+ and H2O2, which activates synthase-stimulator of interferon genes pathway and maintains the cytotoxicity of CD8+ T cells respectively, achieving a cascade-like role in innate and adaptive immunity. The locally administered Mn-LDH facilitated a "hot" network consisting of mature dendritic cells, M1-phenotype macrophages, as well as cytotoxic and helper T cells, significantly inhibiting the growth of primary and distal tumors. Moreover, the photothermal conversion capacity of Mn-LDH sparks more robust therapeutic effects in large established tumor models with a single administration and irradiation. Overall, this study guides the rational design of TME-modulating immunotherapeutics for robust immune activation, providing a clinical candidate for next-generation cancer immunotherapy.

Local, Sustained, and Targeted Co-Delivery of MEK Inhibitor and Doxorubicin Inhibits Tumor Progression in E-Cadherin-Positive Breast Cancer

Effectively utilizing MEK inhibitors in the clinic remains challenging due to off-target toxicity and lack of predictive biomarkers. Recent findings propose E-cadherin, a breast cancer diagnostic indicator, as a predictor of MEK inhibitor success. To address MEK inhibitor toxicity, traditional methodologies have systemically delivered nanoparticles, which require frequent, high-dose injections. Here, we present a different approach, employing a thermosensitive, biodegradable hydrogel with functionalized liposomes for local, sustained release of MEK inhibitor PD0325901 and doxorubicin. The poly(δ-valerolactone-co-lactide)-b-poly(ethylene-glycol)-b-poly(δ-valerolactone-co-lactide) triblock co-polymer gels at physiological temperature and has an optimal degradation time in vivo. Liposomes were functionalized with PR_b, a biomimetic peptide targeting the α5β1 integrin receptor, which is overexpressed in E-cadherin-positive triple negative breast cancer (TNBC). In various TNBC models, the hydrogel-liposome system delivered via local injection reduced tumor progression and improved animal survival without toxic side effects. Our work presents the first demonstration of local, sustained delivery of MEK inhibitors to E-cadherin-positive tumors alongside traditional chemotherapeutics, offering a safe and promising therapeutic strategy.

Injectable Hydrogels: A Paradigm Tailored with Design, Characterization, and Multifaceted Approaches

Biomaterials denoting self-healing and versatile structural integrity are highly curious in the biomedicine segment. The injectable and/or printable 3D printing technology is explored in a few decades back, which can alter their dimensions temporarily under shear stress, showing potential healing/recovery tendency with patient-specific intervention toward the development of personalized medicine. Thus, self-healing injectable hydrogels (IHs) are stunning toward developing a paradigm for tissue regeneration. This review comprises the designing of IHs, rheological characterization and stability, several benchmark consequences for self-healing IHs, their translation into tissue regeneration of specific types, applications of IHs in biomedical such as anticancer and immunomodulation, wound healing and tissue/bone regeneration, antimicrobial potentials, drugs, gene and vaccine delivery, ocular delivery, 3D printing, cosmeceuticals, and photothermal therapy as well as in other allied avenues like agriculture, aerospace, electronic/electrical industries, coating approaches, patents associated with therapeutic/nontherapeutic avenues, and numerous futuristic challenges and solutions.

3D printing materials and 3D printed surgical devices in oral and maxillofacial surgery: design, workflow and effectiveness

Oral and maxillofacial surgery is a specialized surgical field devoted to diagnosing and managing conditions affecting the oral cavity, jaws, face and related structures. In recent years, the integration of 3D printing technology has revolutionized this field, offering a range of innovative surgical devices such as patient-specific implants, surgical guides, splints, bone models and regenerative scaffolds. In this comprehensive review, we primarily focus on examining the utility of 3D-printed surgical devices in the context of oral and maxillofacial surgery and evaluating their efficiency. Initially, we provide an insightful overview of commonly utilized 3D-printed surgical devices, discussing their innovations and clinical applications. Recognizing the pivotal role of materials, we give consideration to suitable biomaterials and printing technology of each device, while also introducing the emerging fields of regenerative scaffolds and bioprinting. Furthermore, we delve into the transformative impact of 3D-printed surgical devices within specific subdivisions of oral and maxillofacial surgery, placing particular emphasis on their rejuvenating effects in bone reconstruction, orthognathic surgery, temporomandibular joint treatment and other applications. Additionally, we elucidate how the integration of 3D printing technology has reshaped clinical workflows and influenced treatment outcomes in oral and maxillofacial surgery, providing updates on advancements in ensuring accuracy and cost-effectiveness in 3D printing-based procedures.

Protocol for delivery of intraoperative immunotherapy to mice by surgical debulking of subcutaneous tumors

Pre-clinical studies developing novel therapies to prevent cancer recurrence require appropriate surgical models. Here, we present a protocol for surgical debulking of subcutaneous tumors in mice, which allows for intraoperative application of immunotherapy-loaded biomaterials. We describe steps for inoculating tumor cells, anesthetizing mice, and performing surgery. We then detail procedures for applying biomaterial, bandaging mice, and data collection and analysis. The optimized bandaging regimen resolves the issue of wound dehiscence after surgery, for C57BL/6 mice, which interfere with surgical sites. For complete details on the use and execution of this protocol, please refer to Rwandamuriye et al.1.

Alginate-Chitosan Biodegradable and Biocompatible Based Hydrogel for Breast Cancer Immunotherapy and Diagnosis: A Comprehensive Review

Breast cancer is the most common type of cancer and the second leading cause of cancer-related mortality in females. There are many side effects due to chemotherapy and traditional surgery, like fatigue, loss of appetite, skin irritation, and drug resistance to cancer cells. Immunotherapy has become a hopeful approach toward cancer treatment, generating long-lasting immune responses in malignant tumor patients. Recently, hydrogel has received more attention toward cancer therapy due to its specific characteristics, such as decreased toxicity, fewer side effects, and better biocompatibility drug delivery to the particular tumor location. Researchers globally reported various investigations on hydrogel research for tumor diagnosis. The hydrogel-based multilayer platform with controlled nanostructure has received more attention for its antitumor effect. Chitosan and alginate play a leading role in the formation of the cross-link in a hydrogel. Also, they help in the stability of the hydrogel. This review discusses the properties, preparation, biocompatibility, and bioavailability of various research and clinical approaches of the multipolymer hydrogel made of alginate and chitosan for breast cancer treatment. With a focus on cases of breast cancer and the recovery rate, there is a need to find out the role of hydrogel in drug delivery for breast cancer treatment.

Porous Hydrogels for Immunomodulatory Applications

Cancer immunotherapy relies on the insight that the immune system can be used to defend against malignant cells. The aim of cancer immunotherapy is to utilize, modulate, activate, and train the immune system to amplify antitumor T-cell immunity. In parallel, the immune system response to damaged tissue is also crucial in determining the success or failure of an implant. Due to their extracellular matrix mimetics and tunable chemical or physical performance, hydrogels are promising platforms for building immunomodulatory microenvironments for realizing cancer therapy and tissue regeneration. However, submicron or nanosized pore structures within hydrogels are not favorable for modulating immune cell function, such as cell invasion, migration, and immunophenotype. In contrast, hydrogels with a porous structure not only allow for nutrient transportation and metabolite discharge but also offer more space for realizing cell function. In this review, the design strategies and influencing factors of porous hydrogels for cancer therapy and tissue regeneration are first discussed. Second, the immunomodulatory effects and therapeutic outcomes of different porous hydrogels for cancer immunotherapy and tissue regeneration are highlighted. Beyond that, this review highlights the effects of pore size on immune function and potential signal transduction. Finally, the remaining challenges and perspectives of immunomodulatory porous hydrogels are discussed.

Engineered Bio-Based Hydrogels for Cancer Immunotherapy

Immunotherapy represents a revolutionary paradigm in cancer management, showcasing its potential to impede tumor metastasis and recurrence. Nonetheless, challenges including limited therapeutic efficacy and severe immune-related side effects are frequently encountered, especially in solid tumors. Hydrogels, a class of versatile materials featuring well-hydrated structures widely used in biomedicine, offer a promising platform for encapsulating and releasing small molecule drugs, biomacromolecules, and cells in a controlled manner. Immunomodulatory hydrogels present a unique capability for augmenting immune activation and mitigating systemic toxicity through encapsulation of multiple components and localized administration. Notably, hydrogels based on biopolymers have gained significant interest owing to their biocompatibility, environmental friendliness, and ease of production. This review delves into the recent advances in bio-based hydrogels in cancer immunotherapy and synergistic combinatorial approaches, highlighting their diverse applications. It is anticipated that this review will guide the rational design of hydrogels in the field of cancer immunotherapy, fostering clinical translation and ultimately benefiting patients.

Advancing nanotechnology for neoantigen-based cancer theranostics

Neoantigens play a pivotal role in the field of tumour therapy, encompassing the stimulation of anti-tumour immune response and the enhancement of tumour targeting capability. Nonetheless, numerous factors directly influence the effectiveness of neoantigens in bolstering anti-tumour immune responses, including neoantigen quantity and specificity, uptake rates by antigen-presenting cells (APCs), residence duration within the tumour microenvironment (TME), and their ability to facilitate the maturation of APCs for immune response activation. Nanotechnology assumes a significant role in several aspects, including facilitating neoantigen release, promoting neoantigen delivery to antigen-presenting cells, augmenting neoantigen uptake by dendritic cells, shielding neoantigens from protease degradation, and optimizing interactions between neoantigens and the immune system. Consequently, the development of nanotechnology synergistically enhances the efficacy of neoantigens in cancer theranostics. In this review, we provide an overview of neoantigen sources, the mechanisms of neoantigen-induced immune responses, and the evolution of precision neoantigen-based nanomedicine. This encompasses various therapeutic modalities, such as neoantigen-based immunotherapy, phototherapy, radiotherapy, chemotherapy, chemodynamic therapy, and other strategies tailored to augment precision in cancer therapeutics. We also discuss the current challenges and prospects in the application of neoantigen-based precision nanomedicine, aiming to expedite its clinical translation.

Primary adipocytes as targetable drug depot to prevent post-surgical cancer recurrence

Surgery followed by adjuvant chemotherapy or radiation therapy remains the mainstream treatment for breast cancer in the clinic. However, cancer recurrence post surgery is still common. In view of the clinical practice that autologous fat tissue grafting is often used to facilitate breast reconstruction after lumpectomy, here we develop an in vivo targetable adipocyte-based drug depot for the prevention of post-surgical cancer recurrence. We show that primary adipocytes can be metabolically labeled with clickable chemical tags (e.g., azido groups), for subsequent conjugation of dibenzocyclooctyne (DBCO)-bearing cargo via efficient click chemistry. The conjugated cargo can retain well on the adipocyte membrane. By incorporating a cleavable linker between DBCO and cargo, the conjugated cargo can be gradually released from the surface of adipocytes to effect on neighboring cells. In the context of breast cancer surgery, azido-labeled adipocytes grafted to the surgical site can capture circulating DBCO-drugs for improved prevention of 4T1 triple-negative breast cancer (TNBC) recurrence and metastasis. This targetable and refillable adipocyte-based drug depot holds great promise for drug delivery, transplantation, and other applications.

Synergistic Chemoimmunotherapy Augmentation via Sequential Nanocomposite Hydrogel-Mediated Reprogramming of Cancer-Associated Fibroblasts in Osteosarcoma

In osteosarcoma, immunotherapy often faces hurdles posed by cancer-associated fibroblasts (CAFs) that secrete dense extracellular matrix components and cytokines. Directly removing CAFs may prove ineffective and even promote tumor metastasis. To address this challenge, a sequential nanocomposite hydrogel that reshapes CAF behavior is developed, enhancing tumor-infiltrating T-cells in osteosarcoma. The approach utilizes an injectable blend of carboxymethyl chitosan and tetrabasic polyethylene glycol, forming a hydrogel for controlled release of a potent CAF suppressor (Nox4 inhibitor, Nox4i) and liposomal Doxorubicin (L-Dox) to induce immunogenic cell death (ICD) upon in situ administration. Nox4i effectively counters CAF activation, overcoming T-cell exclusion mechanisms, followed by programmed L-Dox release for ICD induction in stroma-rich osteosarcoma models. Combining the co-delivery gel with αPD-1 checkpoint inhibitor further enhances its effectiveness in an orthotopic osteosarcoma model. Immunophenotyping data underscore a significant boost in tumor T-cell infiltration and favorable anti-tumor immunity at the whole-animal level.

PGRN inhibits CD8+T cell recruitment and promotes breast cancer progression by up-regulating ICAM-1 on TAM

BACKGROUND

Tumor microenvironment actually reduces antitumor effect against the immune attack by exclusion of CD8+T cells. Progranulin (PGRN) is a multifunctional growth factor with significant pathological effects in multiple tumors; however, its role in immunity evasion of breast cancer (BCa) is not completely understood.

METHODS

We depleted GRN (PGRN gene) genetically in mice or specifically in PY8119 murine BCa cell line, and mouse models of orthotopic or subcutaneous transplantation were used. Chimeric mice-deficient of PGRN (Grn-/-) in bone marrow (BM) compartment was also generated. Association of PGRN expression with chemokine production or BCa development was investigated by histological and immunological assays.

RESULTS

We found PGRN was involved in exhaustion of cytotoxic CD8+T cell in BCa with the increasing expressions of M2 markers and intercellular cell adhesion molecule-1 (ICAM-1) on macrophages. Specifically, ablation of PGRN in PY8119 cells reduced tumor burden, accompanied by the infiltrating of cytotoxic CD8+T cells into tumor nests. Moreover, our result revealed that blockade of PD-1 in PGRN-depleted tumors exhibited better antitumor effect in vivo and significantly decreased tumor burden.

CONCLUSION

These findings suggest that inhibition of PGRN may act as a potential immune-therapeutic strategy by recovering infiltration of CD8+T cell in BCa tissue and thereby enhancing the response to anti-PD-1 therapy.

A Cancer Nanovaccine Based on an FeAl-Layered Double Hydroxide Framework for Reactive Oxygen Species-Augmented Metalloimmunotherapy

The complexity and heterogeneity of individual tumors have hindered the efficacy of existing therapeutic cancer vaccines, sparking intensive interest in the development of more effective in situ vaccines. Herein, we introduce a cancer nanovaccine for reactive oxygen species-augmented metalloimmunotherapy in which FeAl-layered double hydroxide (LDH) is used as a delivery vehicle with dihydroartemisinin (DHA) as cargo. The LDH framework is acid-labile and can be degraded in the tumor microenvironment, releasing iron ions, aluminum ions, and DHA. The iron ions contribute to aggravated intratumoral oxidative stress injury by the synergistic Fenton reaction and DHA activation, causing apoptosis, ferroptosis, and immunogenic cell death in cancer cells. The subsequently released tumor-associated antigens with the aluminum adjuvant form a cancer nanovaccine to generate robust and long-term immune responses against cancer recurrence and metastasis. Moreover, Fe ion-enabled T1-weighted magnetic resonance imaging can facilitate real-time tumor therapy monitoring. This cancer-nanovaccine-mediated metalloimmunotherapy strategy has the potential for revolutionizing the precision immunotherapy landscape.

Recent Biomaterial-Assisted Approaches for Immunotherapeutic Inhibition of Cancer Recurrence

Biomaterials possess distinctive properties, notably their ability to encapsulate active biological products while providing biocompatible support. The immune system plays a vital role in preventing cancer recurrence, and there is considerable demand for an effective strategy to prevent cancer recurrence, necessitating effective strategies to address this concern. This review elucidates crucial cellular signaling pathways in cancer recurrence. Furthermore, it underscores the potential of biomaterial-based tools in averting or inhibiting cancer recurrence by modulating the immune system. Diverse biomaterials, including hydrogels, particles, films, microneedles, etc., exhibit promising capabilities in mitigating cancer recurrence. These materials are compelling candidates for cancer immunotherapy, offering in situ immunostimulatory activity through transdermal, implantable, and injectable devices. They function by reshaping the tumor microenvironment and impeding tumor growth by reducing immunosuppression. Biomaterials facilitate alterations in biodistribution, release kinetics, and colocalization of immunostimulatory agents, enhancing the safety and efficacy of therapy. Additionally, how the method addresses the limitations of other therapeutic approaches is discussed.

Gel-mediated recruitment of conventional type 1 dendritic cells potentiates the therapeutic effects of radiotherapy

The efficacy of radiotherapy has not yet achieved optimal results, partially due to insufficient priming and infiltration of effector immune cells within the tumor microenvironment (TME), which often exhibits suppressive phenotypes. In particular, the infiltration of X-C motif chemokine receptor 1 (XCR1)-expressing conventional type-1 dendritic cells (cDC1s), which are critical in priming CD8+ cytotoxic T cells, within the TME is noticeably restricted. Hence, we present a facile methodology for the efficient fabrication of a calcium phosphate hydrogel loaded with X-C motif chemokine ligand 1 (XCL1) to selectively recruit cDC1s. Manganese phosphate microparticles were also loaded into this hydrogel to reprogram the TME via cGAS-STING activation, thereby facilitating the priming of cDC1s propelled specific CD8+ T cells. They also polarize tumor-associated macrophages towards the M1 phenotype and reduce the proportion of regulatory cells, effectively reversing the immunosuppressive TME into an immune-active one. The yielded XCL1@CaMnP gel exhibits significant efficacy in enhancing the therapeutic outcomes of radiotherapy, particularly when concurrently administered with postoperative radiotherapy, resulting in an impressive 60 % complete response rate. Such XCL1@CaMnP gel, which recruits cDC1s to present tumor antigens generated in situ, holds great potential as a versatile platform for enhanced cancer treatment through modulating the immunosuppressive TME.

Local dose-dense chemotherapy for triple-negative breast cancer via minimally invasive implantation of 3D printed devices

Dose-dense chemotherapy is the preferred first-line therapy for triple-negative breast cancer (TNBC), a highly aggressive disease with a poor prognosis. This treatment uses the same drug doses as conventional chemotherapy but with shorter dosing intervals, allowing for promising clinical outcomes with intensive treatment. However, the frequent systemic administration used for this treatment results in systemic toxicity and low patient compliance, limiting therapeutic efficacy and clinical benefit. Here, we report local dose-dense chemotherapy to treat TNBC by implanting 3D printed devices with time-programmed pulsatile release profiles. The implantable device can control the time between drug releases based on its internal microstructure design, which can be used to control dose density. The device is made of biodegradable materials for clinical convenience and designed for minimally invasive implantation via a trocar. Dose density variation of local chemotherapy using programmable release enhances anti-cancer effects in vitro and in vivo. Under the same dose density conditions, device-based chemotherapy shows a higher anti-cancer effect and less toxic response than intratumoral injection. We demonstrate local chemotherapy utilizing the implantable device that simulates the drug dose, number of releases, and treatment duration of the dose-dense AC (doxorubicin and cyclophosphamide) regimen preferred for TNBC treatment. Dose density modulation inhibits tumor growth, metastasis, and the expression of drug resistance-related proteins, including p-glycoprotein and breast cancer resistance protein. To the best of our knowledge, local dose-dense chemotherapy has not been reported, and our strategy can be expected to be utilized as a novel alternative to conventional therapies and improve anti-cancer efficiency.

A sodium alginate/carboxymethyl chitosan dual-crosslinked injectable hydrogel scaffold with tunable softness/hardness for bone regeneration

Recently, injectable dual-crosslinked (DC) hydrogel scaffolds have attracted many attentions as a class of excellent bone regeneration biomaterials with in-situ tunable functions. However, the design of injectable DC hydrogels with cell behavior-compatible network structure and mechanical property remains a bottleneck. Herein, based on the in-situ gelling method, we constructed an injectable CMCS/PEG+SA/CaCl2 (CPSC) chemical/physical DC hydrogel scaffold with tunable softness/hardness mechanical properties and good biocompatibility. The formation mechanism and properties of the CPSC hydrogel scaffold were investigated by FTIR, XRD, rheometry, and mechanical testing. It is found that proper softness/hardness mechanical properties can be obtained by adjusting the secondary network structure of the hydrogel. The CPSC hydrogel scaffold prepared under optimal conditions can effectively promote cell infiltration, nutrient transport, and the osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs). The in vivo experiments show that the rBMSCs-loaded injectable CPSC hydrogels with appropriate mechanical properties can effectively promote bone reconstruction. This study has provided important guidance for the construction of injectable DC hydrogels with adjustable softness/hardness to promote osteogenesis for bone defect repair.

Multifunctional ZnO@DOX/ICG-LMHP Nanoparticles for Synergistic Multimodal Antitumor Activity

Multifunctional nanoparticles are of significant importance for synergistic multimodal antitumor activity. Herein, zinc oxide (ZnO) was used as pH-sensitive nanoparticles for loading the chemotherapy agent doxorubicin (DOX) and the photosensitizer agent indocyanine green (ICG), and biocompatible low-molecular-weight heparin (LMHP) was used as the gatekeepers for synergistic photothermal therapy/photodynamic therapy/chemotherapy/immunotherapy. ZnO was decomposed into cytotoxic Zn2+ ions, leading to a tumor-specific release of ICG and DOX. ZnO simultaneously produced oxygen (O2) and reactive oxygen species (ROS) for photodynamic therapy (PDT). The released ICG under laser irradiation produced ROS for PDT and raised the tumor temperature for photothermal therapy (PTT). The released DOX directly caused tumor cell death for chemotherapy. Both DOX and ICG also induced immunogenic cell death (ICD) for immunotherapy. The in vivo and in vitro results presented a superior inhibition of tumor progression, metastasis and recurrence. Therefore, this study could provide an efficient approach for designing multifunctional nanoparticles for synergistic multimodal antitumor therapy.

Materials-Based Approaches for Cancer Vaccination

Therapeutic cancer vaccines offer the promise of stimulating the immune system to specifically eradicate tumor cells and establish long-term memory to prevent tumor recurrence. However, despite showing benign safety profiles and the ability to generate Ag-specific cellular responses, cancer vaccines have been hampered by modest clinical efficacy. Lessons learned from these studies have led to the emergence of innovative materials-based strategies that aim to boost the clinical activity of cancer vaccines. In this Brief Review, we provide an overview of the key elements needed for an effective vaccine-induced antitumor response, categorize current approaches to therapeutic cancer vaccination, and explore recent advances in materials-based strategies to potentiate cancer vaccines.

Harnessing 3D in vitro systems to model immune responses to solid tumours: a step towards improving and creating personalized immunotherapies

In vitro 3D models are advanced biological tools that have been established to overcome the shortcomings of oversimplified 2D cultures and mouse models. Various in vitro 3D immuno-oncology models have been developed to mimic and recapitulate the cancer-immunity cycle, evaluate immunotherapy regimens, and explore options for optimizing current immunotherapies, including for individual patient tumours. Here, we review recent developments in this field. We focus, first, on the limitations of existing immunotherapies for solid tumours, secondly, on how in vitro 3D immuno-oncology models are established using various technologies - including scaffolds, organoids, microfluidics and 3D bioprinting - and thirdly, on the applications of these 3D models for comprehending the cancer-immunity cycle as well as for assessing and improving immunotherapies for solid tumours.

An engineered lymph node comprising porous collagen scaffold with hybridized biological signals embedded in B cell membrane coatings

Complications can arise from damaging or removing lymph nodes after surgeries for malignant tumours. Our team has developed an innovative solution to recreate lymph nodes via an engineering approach. Using a Type II collagen scaffold coated with B cell membranes for the sake of attracting T cells in different regions, we could mimic the thymus-dependent and thymus-independent areas in vitro. This engineering strategy based on biophysical mimicry has a great potential for clinical applications. By further conjugating biological signals, anti-CD3/28, onto the scaffold coated with the B cell membrane, we achieved an 11.6-fold expansion of T cells within 14 days of in vitro culture while ensuring their activity, phenotype homeostasis, and differentiation capacity kept intact. Artificial lymph nodes had excellent biocompatibility and caused no pathological or physiological adverse effects after implantation into C57BL6 mice. In vivo assays also demonstrated that this artificial lymph node system positively adhered to omental tissues, creating an environment that fostered T cell growth and prevented cellular failure and death. Additionally, it induced vascular and lymphatic vessel invasion, which was beneficial to the migration and circulation of T cells between this system and peripheral blood. Due to the porous collagen fibre structure, it also facilitated the infiltration of host immune cells. This work opens new avenues to immune organ regeneration via a tissue engineering approach.

Metabolic tagging of extracellular vesicles and development of enhanced extracellular vesicle based cancer vaccines

As key mediators of cellular communication, extracellular vesicles (EVs) have been actively explored for diagnostic and therapeutic applications. However, effective methods to functionalize EVs and modulate the interaction between EVs and recipient cells are still lacking. Here we report a facile and universal metabolic tagging technology that can install unique chemical tags (e.g., azido groups) onto EVs. The surface chemical tags enable conjugation of molecules via efficient click chemistry, for the tracking and targeted modulation of EVs. In the context of tumor EV vaccines, we show that the conjugation of toll-like receptor 9 agonists onto EVs enables timely activation of dendritic cells and generation of superior antitumor CD8+ T cell response. These lead to 80% tumor-free survival against E.G7 lymphoma and 33% tumor-free survival against B16F10 melanoma. Our study yields a universal technology to generate chemically tagged EVs from parent cells, modulate EV-cell interactions, and develop potent EV vaccines.

Multifunctional magnetic nanoparticles elicit anti-tumor immunity in a mouse melanoma model

Immunotherapy has emerged as a promising strategy to eradicate cancer cells. Particularly, the development of cancer vaccines to induce a potent and sustained antigen-specific T cell response has become a center of attention. Herein, we describe a novel immunotherapy based on magnetic nanoparticles (MNP) covalently modified with the OVA254-267 antigen and a CpG oligonucleotide via disulfide bonds. The MNP-CpG-COVA significantly enhances dendritic cell activation and CD8+ T cell antitumoral response against B16-OVA melanoma cells in vitro. Notably, the immune response induced by the covalently modified MNP is more potent and sustained over time than that triggered by the free components, highlighting the advantage of nanoformulations in immunotherapies. What is more, the nanoparticles are stable in the blood after in vivo administration and induce potent levels of systemic tumor-specific effector CD8 + T cells. Overall, our findings highlight the potential of covalently functionalized MNP to induce robust immune responses against mouse melanoma.

The Cancer Moonshot Immuno-Oncology Translational Network at 5: accelerating cancer immunotherapies

The Immuno-Oncology Translational Network (IOTN) was established in 2018 as part of the Cancer Moonshot. In 2022, President Joe Biden set new goals to reduce the cancer death rate by half within 25 years and improve the lives of people with cancer and cancer survivors. The IOTN is focused on accelerating translation of cancer immunology research, from bench to bedside, and improving immunotherapy outcomes across a wide array of cancers in the adult population. The unique structure and team science approach of the IOTN is designed to accelerate discovery and evaluation of novel immune-based therapeutic and prevention strategies. In this article, we describe IOTN progress to date, including new initiatives and the development of a robust set of resources to advance cancer immunology research. We summarize new insights by IOTN researchers, some of which are ripe for translation for several types of cancers. Looking to the future, we identify barriers to the translation of immuno-oncology concepts into clinical trials and key areas for action and improvements that are suitable for high-yield investments. Based on these experiences, we recommend novel National Institutes of Health funding mechanisms and development of new resources to address these barriers.

Biophysics in tumor growth and progression: from single mechano-sensitive molecules to mechanomedicine

Evidence from physical sciences in oncology increasingly suggests that the interplay between the biophysical tumor microenvironment and genetic regulation has significant impact on tumor progression. Especially, tumor cells and the associated stromal cells not only alter their own cytoskeleton and physical properties but also remodel the microenvironment with anomalous physical properties. Together, these altered mechano-omics of tumor tissues and their constituents fundamentally shift the mechanotransduction paradigms in tumorous and stromal cells and activate oncogenic signaling within the neoplastic niche to facilitate tumor progression. However, current findings on tumor biophysics are limited, scattered, and often contradictory in multiple contexts. Systematic understanding of how biophysical cues influence tumor pathophysiology is still lacking. This review discusses recent different schools of findings in tumor biophysics that have arisen from multi-scale mechanobiology and the cutting-edge technologies. These findings range from the molecular and cellular to the whole tissue level and feature functional crosstalk between mechanotransduction and oncogenic signaling. We highlight the potential of these anomalous physical alterations as new therapeutic targets for cancer mechanomedicine. This framework reconciles opposing opinions in the field, proposes new directions for future cancer research, and conceptualizes novel mechanomedicine landscape to overcome the inherent shortcomings of conventional cancer diagnosis and therapies.

Injectable biocompatible nanocomposites of Prussian blue nanoparticles and bacterial cellulose as a safe and effective photothermal cancer therapy

Photothermal therapy (PTT) is a novel cancer treatment using a photoabsorber to cause hyperthermia to kill tumors by laser irradiation. Prussian blue nanoparticles (PB NPs) are considered as next-generation photothermal agents due to the facile synthesis and excellent absorption of near-infrared light. Although PB NPs demonstrate remarkable PTT capabilities, their clinical application is limited due to their systemic toxicity. Bacterial cellulose (BC) has been applied to various bio-applications based on its unique properties and biocompatibility. Herein, we design composites with PB NPs and BC as an injectable, highly biocompatible PTT agent (IBC-PB composites). Injectable bacterial cellulose (IBC) is produced through the trituration of BC, with PB NPs synthesized on the IBC surface to prepare IBC-PB composites. IBC-PB composites show in vitro and in vivo photothermal therapeutic effects similar to those of PB NPs but with significantly greater biocompatibility. Specifically, in vitro therapeutic index of IBC-PB composites is 26.5-fold higher than that of PB NPs. Furthermore, unlike PB NPs, IBC-PB composites exhibit no overt toxicity in mice as assessed by blood biochemical analysis and histological images. Hence, it is worth pursuing further research and development of IBC-PB composites as they hold promise as safe and efficacious PTT agents for clinical application.

Cancer Immunotherapy Using Bioengineered Micro/Nano Structured Hydrogels

Hydrogels, a class of materials with a 3D network structure, are widely used in various applications of therapeutic delivery, particularly cancer therapy. Micro and nanogels as miniaturized structures of the bioengineered hydrogels may provide extensive benefits over the common hydrogels in encapsulation and controlled release of small molecular drugs, macromolecular therapeutics, and even cells. Cancer immunotherapy is rapidly developing, and micro/nanostructured hydrogels have gained wide attention regarding their engineered payload release properties that enhance systemic anticancer immunity. Additionally, they are a great candidate due to their local administration properties with a focus on local immune cell manipulation in favor of active and passive immunotherapies. Although applied locally, such micro/nanostructured can also activate systemic antitumor immune responses by releasing nanovaccines safely and effectively inhibiting tumor metastasis and recurrence. However, such hydrogels are mostly used as locally administered carriers to stimulate the immune cells by releasing tumor lysate, drugs, or nanovaccines. In this review, the latest developments in cancer immunotherapy are summarized using micro/nanostructured hydrogels with a particular emphasis on their function depending on the administration route. Moreover, the potential for clinical translation of these hydrogel-based cancer immunotherapies is also discussed.

Cryo-shocked cancer cell microgels for tumor postoperative combination immunotherapy and tissue regeneration

Prevention of recurrence/metastasis and tissue regeneration are critical for post-surgery treatment of malignant tumors. Here, to address these needs, a novel type of microgel co-loading cryo-shocked cancer cells, immunoadjuvant, and immune checkpoint inhibitor is presented by microfluidic electrospray technology and liquid nitrogen treatment. Owing to the encapsulation of cryo-shocked cancer cells and immunoadjuvant, the microgels can recruit dendritic cells and activate them in situ, and evoke a robust immune response. Moreover, with the combination of the immune checkpoint inhibitor, the antitumor immune response is further enhanced by inhibiting the interaction of PD1 and PDL1. With this, the excellent anti-recurrence and anti-metastasis efficacy of the microgels are demonstrated in an orthotopic breast cancer mouse model. Besides, because of the excellent biocompatibility and appropriate degradation performance, the microgels can provide support for normal cell adhesion and growth, which is beneficial to tissue reconstruction. These properties indicate the great value of the cryo-shocked cancer cell microgels for efficient tumor postoperative combination immunotherapy and tissue regeneration.

Programming Injectable DNA Hydrogels Yields Tumor Microenvironment-Activatable and Immune-Instructive Depots for Augmented Chemo-Immunotherapy

Injectable hydrogels have attracted increasing attention for promoting systemic antitumor immune response through the co-delivery of chemotherapeutics and immunomodulators. However, the biosafety and bioactivity of conventional hydrogel depots are often impaired by insufficient possibilities for post-gelling injection and means for biofunction integration. Here, an unprecedented injectable stimuli-responsive immunomodulatory depot through programming a super-soft DNA hydrogel adjuvant is reported. This hydrogel system encoded with adenosine triphosphate aptamers can be intratumorally injected in a gel formulation and then undergoes significant molecular conformation change to stimulate the distinct release kinetics of co-encapsulated therapeutics. In this scenario, doxorubicin is first released to induce immunogenic cell death that intimately works together with the polymerized cytosine-phosphate-guanine oligodeoxynucleotide (CpG ODN) in gel scaffold for effectively recruiting and activating dendritic cells. The polymerized CpG ODN not only enhances tumor immunogenicity but minimizes free CpG-induced splenomegaly. Furthermore, the subsequently released anti-programmed cell death protein ligand 1 (aPDL1) blocks the corresponding immune inhibitory checkpoint molecule on tumor cells to sensitize antitumor T-cell immunity. This work thus contributes to the first proof-of-concept demonstration of a programmable super-soft DNA hydrogel system that perfectly matches the synergistic therapeutic modalities based on chemotherapeutic toxicity, in situ vaccination, and immune checkpoint blockade.

Cancer Vaccine Therapeutics: Limitations and Effectiveness-A Literature Review

In recent years, there has been a surge of interest in tumor microenvironment-associated cancer vaccine therapies. These innovative treatments aim to activate and enhance the body's natural immune response against cancer cells by utilizing specific antigens present in the tumor microenvironment. The goal is to achieve a complete clinical response, where all measurable cancer cells are either eliminated or greatly reduced in size. With their potential to revolutionize cancer treatment, these therapies represent a promising avenue for researchers and clinicians alike. Despite over 100 years of research, the success of therapeutic cancer vaccines has been variable, particularly in advanced cancer patients, with various limitations, including the heterogeneity of the tumor microenvironment, the presence of immunosuppressive cells, and the potential for tumor escape mechanisms. Additionally, the effectiveness of these therapies may be limited by the variability of the patient's immune system response and the difficulty in identifying appropriate antigens for each patient. Despite these challenges, tumor microenvironment-targeted vaccine cancer therapies have shown promising results in preclinical and clinical studies and have the potential to become a valuable addition to current cancer treatment and "curative" options. While chemotherapeutic and monoclonal antibody treatments remain popular, ongoing research is needed to optimize the design and delivery of these therapies and to identify biomarkers that can predict response and guide patient selection. This comprehensive review explores the mechanisms of cancer vaccines, various delivery methods, and the role of adjuvants in improving treatment outcomes. It also discusses the historical background of cancer vaccine research and examines the current state of major cancer vaccination immunotherapies. Furthermore, the limitations and effectiveness of each vaccine type are analyzed, providing insights into the future of cancer vaccine development.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Bio-adhesive Macroporous Hydrogels for In Situ Recruitment and Modulation of Dendritic Cells

Introduction

Biomaterials that enable in situ recruitment and modulation of immune cells have demonstrated tremendous promise for developing potent cancer immunotherapy such as therapeutic cancer vaccine. One challenge related to biomaterial scaffold-based cancer vaccines is the development of macroporous materials that are biocompatible and stable, enable controlled release of chemokines to actively recruit a large number of dendritic cells (DCs), contain macropores that are large enough to home the recruited DCs, and support the survival and proliferation of DCs.

Methods

Bio-adhesive macroporous gelatin hydrogels were synthesized and characterized for mechanical properties, porous structure, and adhesion towards tissues. The recruitment of immune cells including DCs to chemokine-loaded bioadhesive macroporous gels was analyzed. The ability of gels loaded with granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor extracellular vesicles (EVs) to elicit tumor-specific CD8+ T cell responses was also analyzed.

Results

Here we develop a bioadhesive macroporous hydrogel that can strongly adhere to tissues, contain macropores that are large enough to home immune cells, are mechanically tough, and enable controlled release of chemokines to recruit and modulate immune cells in situ. The macroporous hydrogel is composed of a double crosslinked network of gelatin and polyacrylic acid, and the macropores are introduced via cryo-polymerization. By incorporating GM-CSF and tumor EVs into the macroporous hydrogel, a high number of DCs can be recruited in situ to process and present EV-encased antigens. These tumor antigen-presenting DCs can then traffic to lymphatic tissues to prime antigen-specific CD8+ T cells.

Conclusion

This bioadhesive macroporous hydrogel system provides a new platform for in situ recruitment and modulation of DCs and the development of enhanced immunotherapies including tumor EV vaccines. We also envision the promise of this material system for drug delivery, tissue regeneration, long-term immunosuppression, and many other applications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-023-00770-2.

Rethinking Antigen Source: Cancer Vaccines Based on Whole Tumor Cell/tissue Lysate or Whole Tumor Cell

Cancer immunotherapies have improved human health, and one among the important technologies for cancer immunotherapy is cancer vaccine. Antigens are the most important components in cancer vaccines. Generally, antigens in cancer vaccines can be divided into two categories: pre-defined antigens and unidentified antigens. Although, cancer vaccines loaded with predefined antigens are commonly used, cancer vaccine loaded with mixed unidentified antigens, especially whole cancer cells or cancer cell lysates, is a very promising approach, and such vaccine can obviate some limitations in cancer vaccines. Their advantages include, but are not limited to, the inclusion of pan-spectra (all or most kinds of) antigens, inducing pan-clones specific T cells, and overcoming the heterogeneity of cancer cells. In this review, the recent advances in cancer vaccines based on whole-tumor antigens, either based on whole cancer cells or whole cancer cell lysates, are summarized. In terms of whole cancer cell lysates, the focus is on applying whole water-soluble cell lysates as antigens. Recently, utilizing the whole cancer cell lysates as antigens in cancer vaccines has become feasible. Considering that pre-determined antigen-based cancer vaccines (mainly peptide-based or mRNA-based) have various limitations, developing cancer vaccines based on whole-tumor antigens is a promising alternative.

Sulfate-reducing bacteria loaded in hydrogel as a long-lasting H2S factory for tumor therapy

The continuous supply of hydrogen sulfide (H2S) gas at high concentrations to tumors is considered a promising and safe strategy for tumor therapy. However, the absence of a durable and cost-effective H2S-producing donor hampers its extensive application. Sulfate-reducing bacteria (SRB) can serve as an excellent H2S factory due to their ability to metabolize sulfate into H2S. Herein, a novel injectable chondroitin sulfate (ChS) hydrogel loaded with SRB (SRB@ChS Gel) is proposed to sustainably produce H2S in tumor tissues to overcome the limitations of current H2S gas therapy. In vitro, the ChS Gel not only supports the growth of encapsulated SRB, but also supplies a sulfate source to the SRB to produce high concentrations of H2S for at least 7 days, resulting in mitochondrial damage and immunogenic cell death. Once injected into tumor tissue, the SRB@ChS Gel can constantly produce H2S for >5 days, significantly inhibiting tumor growth. Furthermore, such treatment activates systemic anti-tumor immune responses, suppresses the growth of distant and recurrent tumors, as well as lung metastases, meanwhile with negligible side effects. Therefore, the injectable SRB@ChS Gel, as a safe and long-term, self-sustained H2S-generating factory, provides a promising strategy for anti-tumor therapy.

Efficacy evaluation of chimeric antigen receptor-modified human peritoneal macrophages in the treatment of gastric cancer

BACKGROUND

Gastric cancer is one of the most common cancers. Peritoneal carcinomatosis (PC) appears to be the most common pattern of recurrence, and more than half of the GC patients eventually die from PC. Novel strategies for the management of patients with PC are urgently needed. Recently, rapid progress has been made in adoptive transfer therapy by using macrophages as the effector cells due to their capabilities of phagocytosis, antigen presentation, and high penetration. Here, we generated a novel macrophage-based therapy and investigated anti-tumoral effects on GC and potential toxicity.

METHODS

We developed a novel Chimeric Antigen Receptor-Macrophage (CAR-M) based on genetically modifying human peritoneal macrophages (PMs), expressing a HER2-FcεR1γ-CAR (HF-CAR). We tested HF-CAR macrophages in a variety of GC models in vitro and in vivo.

RESULTS

HF-CAR-PMs specifically targeted HER2-expressed GC, and harboured the FcεR1γ moieties to trigger engulfment. Intraperitoneal administration of HF-CAR-PMs significantly facilitated the HER2-positive tumour regression in PC mouse model and prolonged the overall survival rate. In addition, the combined use of oxaliplatin and HF-CAR-PMs exhibited significantly augment anti-tumour activity and survival benefit.

CONCLUSIONS

HF-CAR-PMs could represent an exciting therapeutic option for patients with HER2-positive GC cancer, which should be tested in carefully designed clinical trials.

A surgically optimized intraoperative poly(I:C)-releasing hydrogel prevents cancer recurrence

Recurrences frequently occur following surgical removal of primary tumors. In many cancers, adjuvant therapies have limited efficacy. Surgery provides access to the tumor microenvironment, creating an opportunity for local therapy, in particular immunotherapy, which can induce local and systemic anti-cancer effects. Here, we develop a surgically optimized biodegradable hyaluronic acid-based hydrogel for sustained intraoperative delivery of Toll-like receptor 3 agonist poly(I:C) and demonstrate that it significantly reduces tumor recurrence after surgery in multiple mouse models. Mechanistically, poly(I:C) induces a transient interferon alpha (IFNα) response, reshaping the tumor/wound microenvironment by attracting inflammatory monocytes and depleting regulatory T cells. We demonstrate that a pre-existing IFN signature predicts response to the poly(I:C) hydrogel, which sensitizes tumors to immune checkpoint therapy. The safety, immunogenicity, and surgical feasibility are confirmed in a veterinary trial in canine soft tissue tumors. The surgically optimized poly(I:C)-loaded hydrogel provides a safe and effective approach to prevent cancer recurrence.

Ultrasound-responsive low-dose doxorubicin liposomes trigger mitochondrial DNA release and activate cGAS-STING-mediated antitumour immunity

DNA derived from chemotherapeutics-killed tumor cells is one of the most important damage-associated molecular patterns that can activate the cGAS-STING (cyclic GMP-AMP synthase-stimulator of interferon genes) pathway in antigen-presenting cells (APCs) and promote antitumor immunity. However, conventional chemotherapy displays limited tumor cell killing and ineffective transfer of stable tumor DNA to APCs. Here we show that liposomes loaded with an optimized ratio of indocyanine green and doxorubicin, denoted as LID, efficiently generate reactive oxygen species upon exposure to ultrasound. LID plus ultrasound enhance the nuclear delivery of doxorubicin, induce tumor mitochondrial DNA oxidation, and promote oxidized tumor mitochondrial DNA transfer to APCs for effective activation of cGAS-STING signaling. Depleting tumor mitochondrial DNA or knocking out STING in APCs compromises the activation of APCs. Furthermore, systemic injection of LID plus ultrasound over the tumor lead to targeted cytotoxicity and STING activation, eliciting potent antitumor T cell immunity, which upon the combination with immune checkpoint blockade leads to regression of bilateral MC38, CT26, and orthotopic 4T1 tumors in female mice. Our study sheds light on the importance of oxidized tumor mitochondrial DNA in STING-mediated antitumor immunity and may inspire the development of more effective strategies for cancer immunotherapy.

Biodegradable lipophilic polymeric mRNA nanoparticles for ligand-free targeting of splenic dendritic cells for cancer vaccination

Nanoparticle (NP)-based mRNA cancer vaccines hold great promise to realize personalized cancer treatments. To advance this technology requires delivery formulations for efficient intracellular delivery to antigen-presenting cells. We developed a class of bioreducible lipophilic poly(beta-amino ester) nanocarriers with quadpolymer architecture. The platform is agnostic to the mRNA sequence, with one-step self-assembly allowing for delivery of multiple antigen-encoding mRNAs as well as codelivery of nucleic acid-based adjuvants. We examined structure-function relationships for NP-mediated mRNA delivery to dendritic cells (DCs) and identified that a lipid subunit of the polymer structure was critical. Following intravenous administration, the engineered NP design facilitated targeted delivery to the spleen and preferential transfection of DCs without the need for surface functionalization with targeting ligands. Treatment with engineered NPs codelivering antigen-encoding mRNA and toll-like receptor agonist adjuvants led to robust antigen-specific CD8+ T cell responses, resulting in efficient antitumor therapy in in vivo models of murine melanoma and colon adenocarcinoma.

Application of Nano-Delivery Systems in Lymph Nodes for Tumor Immunotherapy

Immunotherapy has become a promising research "hotspot" in cancer treatment. "Soldier" immune cells are not uniform throughout the body; they accumulate mostly in the immune organs such as the spleen and lymph nodes (LNs), etc. The unique structure of LNs provides the microenvironment suitable for the survival, activation, and proliferation of multiple types of immune cells. LNs play an important role in both the initiation of adaptive immunity and the generation of durable anti-tumor responses. Antigens taken up by antigen-presenting cells in peripheral tissues need to migrate with lymphatic fluid to LNs to activate the lymphocytes therein. Meanwhile, the accumulation and retaining of many immune functional compounds in LNs enhance their efficacy significantly. Therefore, LNs have become a key target for tumor immunotherapy. Unfortunately, the nonspecific distribution of the immune drugs in vivo greatly limits the activation and proliferation of immune cells, which leads to unsatisfactory anti-tumor effects. The efficient nano-delivery system to LNs is an effective strategy to maximize the efficacy of immune drugs. Nano-delivery systems have shown beneficial in improving biodistribution and enhancing accumulation in lymphoid tissues, exhibiting powerful and promising prospects for achieving effective delivery to LNs. Herein, the physiological structure and the delivery barriers of LNs were summarized and the factors affecting LNs accumulation were discussed thoroughly. Moreover, developments in nano-delivery systems were reviewed and the transformation prospects of LNs targeting nanocarriers were summarized and discussed.

Engineered cell-based therapies in ex vivo ready-made CellDex capsules have therapeutic efficacy in solid tumors

Encapsulated cell-based therapies for solid tumors have shown promising results in pre-clinical settings. However, the inability to culture encapsulated therapeutic cells prior to their transplantation has limited their translation into clinical settings. In this study, we created a wide variety of engineered therapeutic cells (ThC) loaded in micropore-forming gelatin methacryloyl (GelMA) hydrogel (CellDex) capsules that can be cultured in vitro prior to their transplantation in surgically debulked solid tumors. We show that both allogeneic and autologous engineered cells, such as stem cells (SCs), macrophages, NK cells, and T cells, proliferate within CellDex capsules and migrate out of the gel in vitro and in vivo. Furthermore, tumor cell specific therapeutic proteins and oncolytic viruses released from CellDex capsules retain and prolong their anti-tumor effects. In vivo, ThCs in pre-manufactured Celldex capsules persist long-term and track tumor cells. Moreover, chimeric antigen receptor (CAR) T cell bearing CellDex (T-CellDex) and human SC releasing therapeutic proteins (hSC-CellDex) capsules show therapeutic efficacy in metastatic and primary brain tumor resection models that mimic standard of care of tumor resection in patients. Overall, this unique approach of pre-manufactured micropore-forming CellDex capsules offers an effective off-the-shelf clinically viable strategy to treat solid tumors locally.

Gas therapy potentiates aggregation-induced emission luminogen-based photoimmunotherapy of poorly immunogenic tumors through cGAS-STING pathway activation

The immunologically "cold" microenvironment of triple negative breast cancer results in resistance to current immunotherapy. Here, we reveal the immunoadjuvant property of gas therapy with cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway activation to augment aggregation-induced emission (AIE)-active luminogen (AIEgen)-based photoimmunotherapy. A virus-mimicking hollow mesoporous tetrasulfide-doped organosilica is developed for co-encapsulation of AIEgen and manganese carbonyl to fabricate gas nanoadjuvant. As tetra-sulfide bonds are responsive to intratumoral glutathione, the gas nanoadjuvant achieves tumor-specific drug release, promotes photodynamic therapy, and produces hydrogen sulfide (H₂S). Upon near-infrared laser irradiation, the AIEgen-mediated phototherapy triggers the burst of carbon monoxide (CO)/Mn²⁺. Both H₂S and CO can destroy mitochondrial integrity to induce leakage of mitochondrial DNA into the cytoplasm, serving as gas immunoadjuvants to activate cGAS-STING pathway. Meanwhile, Mn²⁺ can sensitize cGAS to augment STING-mediated type I interferon production. Consequently, the gas nanoadjuvant potentiates photoimmunotherapy of poorly immunogenic breast tumors in female mice.

A Balance between Pro-Inflammatory and Pro-Reparative Macrophages is Observed in Regenerative D-MAPS

Microporous annealed particle scaffolds (MAPS) are a new class of granular materials generated through the interlinking of tunable microgels, which produce an interconnected network of void space. These microgel building blocks can be designed with different mechanical or bio-active parameters to facilitate cell infiltration and modulate host response. Previously, changing the chirality of the microgel crosslinking peptides from L- to D-amino acids led to significant tissue regeneration and functional recovery in D-MAPS-treated cutaneous wounds. In this study, the immunomodulatory effect of D-MAPS in a subcutaneous implantation model is investigated. How macrophages are the key antigen-presenting cells to uptake and present these biomaterials to the adaptive immune system is uncovered. A robust linker-specific IgG2b/IgG1 response to D-MAPS is detected as early as 14 days post-implantation. The fine balance between pro-regenerative and pro-inflammatory macrophage phenotypes is observed in D-MAPS as an indicator for regenerative scaffolds. The work offers valuable insights into the temporal cellular response to synthetic porous scaffolds and establishes a foundation for further optimization of immunomodulatory pro-regenerative outcomes.

Current therapeutic approaches and promising perspectives of using bioengineered peptides in fighting chemoresistance in triple-negative breast cancer

Breast cancer is a collation of malignancies that manifest in the mammary glands at the early stages. Among breast cancer subtypes, triple-negative breast cancer (TNBC) shows the most aggressive behavior, with apparent stemness features. Owing to the lack of response to hormone therapy and specific targeted therapies, chemotherapy remains the first line of the TNBC treatment. However, the acquisition of resistance to chemotherapeutic agents increase therapy failure, and promotes cancer recurrence and distant metastasis. Invasive primary tumors are the birthplace of cancer burden, though metastasis is a key attribute of TNBC-associated morbidity and mortality. Targeting the chemoresistant metastases-initiating cells via specific therapeutic agents with affinity to the upregulated molecular targets is a promising step in the TNBC clinical management. Exploring the capacity of peptides as biocompatible entities with the specificity of action, low immunogenicity, and robust efficacy provides a principle for designing peptide-based drugs capable of increasing the efficacy of current chemotherapy agents for selective targeting of the drug-tolerant TNBC cells. Here, we first focus on the resistance mechanisms that TNBC cells acquire to evade the effect of chemotherapeutic agents. Next, the novel therapeutic approaches employing tumor-targeting peptides to exploit the mechanisms of drug resistance in chemorefractory TNBC are described.

Bioorthogonal-Activated In Situ Vaccine Mediated by a COF-Based Catalytic Platform for Potent Cancer Immunotherapy

Personalized tumor vaccines have become a promising modality for cancer immunotherapy. However, in situ personalized tumor vaccines generated from immunogenic cancer cell death (ICD) and adjuvants are mired by toxic side effects and unsatisfactory efficiency. Herein, by functionalizing the reticular structure to optimize the catalytic activity of the materials, a series of biocompatible covalent organic framework (COF)-based catalysts have been designed and screened for establishing a bioorthogonal-activated in situ cancer vaccine in an efficient and safe way. Especially, pro-doxorubicin (pro-DOX) could be bioorthogonally activated in situ by the COF-based Fe(II) catalysts, which elicited ICD and released tumor-associated antigens (TAAs). This in situ prodrug activation strategy could minimize drug side effects and maximize treatment effects. More importantly, the system could also catalytically activate pro-imiquimod (pro-IMQ, a TLR7/8 immune agonist), which served as an adjuvant to amplify the antitumor immunity. Notably, this bioorthogonal-activated in situ cancer vaccine not only facilitated a strong antitumor immune response but also prevented the dose-dependent side effects of chemotherapeutic drugs, including systemic inflammation caused by the random distribution of adjuvants. To the best of our knowledge, it is the first time to devise an efficient catalytic platform for generating an in situ bioorthogonal-activated cancer vaccine, which would provide a paradigm for achieving secure and robust immunotherapy.

Injectable Polypeptide Hydrogel Depots Containing Dual Immune Checkpoint Inhibitors and Doxorubicin for Improved Tumor Immunotherapy and Post-Surgical Tumor Treatment

In this work, we developed a strategy for local chemo-immunotherapy through simultaneous incorporation of dual immune checkpoint blockade (ICB) antibodies, anti-cytotoxic T-lymphocyte-associated protein 4 (aCTLA-4) and anti-programmed cell death protein 1 (aPD-1), and a chemotherapy drug, doxorubicin (Dox), into a thermo-gelling polypeptide hydrogel. The hydrogel encapsulating Dox or IgG model antibody showed sustained release profiles for more than 12 days in vitro, and the drug release and hydrogel degradation were accelerated in the presence of enzymes. In comparison to free drug solutions or hydrogels containing Dox or antibodies only, the Dox/aCTLA-4/aPD-1 co-loaded hydrogel achieved improved tumor suppression efficiency, strengthened antitumor immune response, and prolonged animal survival time after peritumoral injection into mice bearing B16F10 melanoma. Additionally, after injection of Dox/aCTLA-4/aPD-1 co-loaded hydrogel into the surgical site following tumor resection, a significantly enhanced inhibition on tumor reoccurrence was demonstrated. Thus, the polypeptide hydrogel-based chemo-immunotherapy strategy has potential in anti-tumor therapy and the prevention of tumor reoccurrence.

Doxorubicin-isoniazid conjugate regulates immune response and tumor microenvironment to enhance cancer therapy

Immune checkpoint inhibitors (ICIs) represent a new class of immunotherapy drugs, and are used to relieve immune suppression or enhance the immune response through the blockade of checkpoint ligands or receptors. ICIs have achieved great success in clinical cancer treatment. Monoamine oxidase A (MAOA) is a potent immune checkpoint of immunotherapy. Recently, it has been reported that MAOA inhibitors could enhance CD8⁺ T cell activity by upregulating 5-HT autocrine pathway in T cells. In this study, we synthesized doxorubicin (DOX) and isoniazid (INH, a MAOA inhibitor) conjugates through a pH sensitive hydrazone bond. Results of the in vivo studies showed that DOX-INH could effectively enhance the activity of CD8⁺ T cells and perform a synergistic anti-tumor effect with PD-L1 small molecular inhibitor (BMS202). In addition, in an orthotopic 4T1 breast cancer model, it was demonstrated that DOX-INH could inhibit the epithelial-mesenchymal transition process by blocking Shh, IL-6, and TGF-β signaling pathways, thereby inhibiting the growth and metastasis of breast cancer. Thus, a simple and effective small molecule conjugate produced by the combination of a chemotherapy drug and a MAOA inhibitor shows broad prospect in cancer therapy.