Implantable Sandwich-like Scaffold/Fiber Composite Spatiotemporally Releasing Combretastatin A4 and Doxorubicin for Efficient Inhibition of Postoperative Tumor Recurrence

Spatiotemporal release of non-nucleotide STING agonist and AKT inhibitor from implantable 3D-printed scaffold for amplified cancer immunotherapy

Immunotherapy through the activation of the stimulator of interferon genes (STING) signaling pathway is increasingly recognized for its robust anti-tumor efficacy. However, the effectiveness of STING activation is often compromised by inadequate anti-tumor immunity and a scarcity of primed immune cells in the tumor microenvironment. Herein, we design and fabricate a co-axial 3D-printed scaffold integrating a non-nucleotide STING agonist, SR-717, and an AKT inhibitor, MK-2206, in its respective shell and core layers, to synergistically enhance STING activation, thereby suppressing tumor recurrence and growth. SR-717 initiates the STING activation to enhance the phosphorylation of the factors along the STING pathway, while MK-2206 concurrently inhibits the AKT phosphorylation to facilitate the TBK1 phosphorylation of the STING pathway. The sequential and sustained release of SR-717 and MK-2206 from the scaffold results in a synergistic STING activation, demonstrating substantial anti-tumor efficacy across multiple tumor models. Furthermore, the scaffold promotes the recruitment and enrichment of activated dendritic cells and M1 macrophages, subsequently stimulating anti-tumor T cell activity, thereby amplifying the immunotherapeutic effect. This precise and synergistic activation of STING by the scaffold offers promising potential in tumor immunotherapy.

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.

Quaternary ammonium-tethered hyperbranched polyurea nanoassembly synergized with antibiotics for enhanced antimicrobial efficacy

The effective transportation of antibiotics to bacteria embedded within a biofilm consisting of a dense matrix of extracellular polymeric substances is still a challenge in the treatment of bacterial biofilm associated infections. Here, we developed an antibiotic nanocarrier constructed from quaternary ammonium-tethered hyperbranched polyureas (HPUs-QA), which showed high loading capacity for a model antibiotic, rifampicin, and high efficacy in the transportation of rifampicin to biofilms. The rifampicin-loaded HPUs-QA nanoassembly (HPUs-Rif/QA) demonstrated a synergistic antimicrobial effect in killing planktonic bacteria and eradicating the corresponding biofilms. Compared to the treatment of bacteria-infected chronic wounds by either HPUs-QA or rifampicin alone, HPUs-Rif/QA showed superior efficacy in promoting wound healing by more effectively inhibiting bacteria colonization. This study highlights the potential of the HPUs-QA nanoassembly in synergistic action with antibiotics for the treatment of biofilm associated infections.

Rhogef17: A novel target for endothelial barrier function

ARHGEF17 encodes the protein RhoGEF17, which is highly expressed in vascular endothelial cells. It is a guanine nucleotide exchange factor (GEF) that accelerates the exchange of GDP with GTP on many small GTPases through its Dbl homology (DH) domain, enabling the activation of Rho-GTPases such as RhoA, RhoB, and RhoC. Rho GTPase-regulated changes in the actin cytoskeleton and cell adhesion kinetics are the main mechanisms mediating many endothelial cell (EC) alterations, including cell morphology, migration, and division changes, which profoundly affect EC barrier function. This review focuses on ARHGEF17 expression, activation and biological functions in ECs, linking its regulation of cellular morphology, migration, mitosis and other cellular behaviors to disease onset and progression. Understanding ARHGEF17 mechanisms of action will contribute to the design of therapeutic approaches targeting RhoGEF17, a potential drug target for the treatment of various endothelium-related diseases, Such as vascular inflammation, carcinogenesis and transendothelial metastasis of tumors.

Gel/hydrogel-based in situ biomaterial platforms for cancer postoperative treatment and recovery

Tumor surgical resection is the major strategy for cancer treatment. Meanwhile, perioperative treatment especially the postoperative adjuvant anticancer strategies play essential roles in satisfying therapeutic results and rapid recovery. Postoperative tumor recurrence, metastasis, bleeding, inter-tissue adhesion, infection, and delayed wound healing are vital risks that could lead to poor prognosis or even treatment failure. Therefore, methods targeting these postoperative complications are in desperate need. In situ biomaterial-based drug delivery platforms are promising candidates for postoperative treatment and recovery, resulting from their excellent properties including good biocompatibility, adaptive shape, limited systemic effect, designable function, and easy drug loading. In this review, we focus on introducing the gel/hydrogel-based in situ biomaterial platforms involving their properties, advantages, and synthesis procedures. Based on the loaded contents in the gel/hydrogel such as anticancer drugs, immunologic agents, cell components, and multifunctional nanoparticles, we further discuss the applications of the in situ platforms for postoperative tumor recurrence and metastasis inhibition. Finally, other functions aiming at fast postoperative recovery were introduced, including hemostasis, antibacterial infection, adhesion prevention, tissue repair, and wound healing. In conclusion, gel/hydrogel is a developing and promising platform for postoperative treatment, exhibiting gratifying therapeutic effects and inconspicuous toxicity to normal tissues, which deserves further research and exploration.

Nanozyme-integrated microneedle patch for enhanced therapy of cutaneous squamous cell carcinoma by breaking the gap between H2O2 self-supplying chemodynamic therapy and photothermal therapy

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin cancers with increasing incidence worldwide. However, it is still challenging to prevent the relapse of cSCC due to poor drug penetration across the stratum corneum. Herein, we report the design of a microneedle patch loaded with MnO2/Cu2O nanosheets and combretastatin A4 (MN-MnO2/Cu2O-CA4) for the enhanced therapy of cSCC. The prepared MN-MnO2/Cu2O-CA4 patch could effectively deliver adequate drugs locally into the tumor sites. Moreover, the glucose oxidase (GOx)-mimicking activity of MnO2/Cu2O could catalyze glucose to produce H2O2, which combined with the released Cu to induce a Fenton-like reaction to efficiently generate hydroxyl radicals for chemodynamic therapy. Meanwhile, the released CA4 could inhibit cancer cell migration and tumor growth by disrupting the tumor vasculature. Moreover, MnO2/Cu2O was endowed with the ability of photothermal conversion under the irradiation of near-infrared (NIR) laser, which could not only kill the cancer cells but also promote the efficiency of the Fenton-like reaction. Significantly, the photothermal effect did not compromise the GOx-like activity of MnO2/Cu2O, which guaranteed enough production of H2O2 for the sufficient generation of hydroxyl radicals. This work may open avenues for constructing MN-based multimodal treatment for the efficient therapy of skin cancers.

Therapeutic Agent-Loaded Fibrous Scaffolds for Biomedical Applications

Tissue engineering is a sophisticated field that involves the integration of various disciplines, such as clinical medicine, material science, and life science, to repair or regenerate damaged tissues and organs. To achieve the successful regeneration of damaged or diseased tissues, it is necessary to fabricate biomimetic scaffolds that provide structural support to the surrounding cells and tissues. Fibrous scaffolds loaded with therapeutic agents have shown considerable potential in tissue engineering. In this comprehensive review, we examine various methods for fabricating bioactive molecule-loaded fibrous scaffolds, including preparation methods for fibrous scaffolds and drug-loading techniques. Additionally, we delved into the recent biomedical applications of these scaffolds, such as tissue regeneration, inhibition of tumor recurrence, and immunomodulation. The aim of this review is to discuss the latest research trends in fibrous scaffold manufacturing methods, materials, drug-loading methods with parameter information, and therapeutic applications with the goal of contributing to the development of new technologies or improvements to existing ones.

Sandwich-Structured Implants to Obstruct Multipath Energy Supply and Trigger Self-Enhanced Hypoxia-Initiated Chemotherapy Against Postsurgical Tumor Recurrence and Metastasis

As a currently common strategy to treat cancer, surgical resection may cause tumor recurrence and metastasis due to residual postoperative tumors. Herein, an implantable sandwich-structured dual-drug depot is developed to trigger a self-intensified starvation therapy and hypoxia-induced chemotherapy sequentially. The two outer layers are 3D-printed using a calcium-crosslinked mixture ink containing soy protein isolate, polyvinyl alcohol, sodium alginate, and combretastatin A4 phosphate (CA4P). The inner layer is one patch of poly (lactic-co-glycolic acid)-based electrospun fibers loaded with tirapazamine (TPZ). The preferentially released CA4P destroys the preexisting blood vessels and prevents neovascularization, which obstructs the external energy supply to cancer cells but aggravates hypoxic condition. The subsequently released TPZ is bioreduced to cytotoxic benzotriazinyl under hypoxia, further damaging DNA, generating reactive oxygen species, disrupting mitochondria, and downregulating hypoxia-inducible factor 1α, vascular endothelial growth factor, and matrix metalloproteinase 9. Together these processes induce apoptosis, block the intracellular energy supply, counteract the disadvantage of CA4P in favoring intratumor angiogenesis, and suppress tumor metastasis. The in vivo and in vitro results and the transcriptome analysis demonstrate that the postsurgical adjuvant treatment with the dual-drug-loaded sandwich-like implants efficiently inhibits tumor recurrence and metastasis, showing great potential for clinical translation.

Self-intensified synergy of a versatile biomimetic nanozyme and doxorubicin on electrospun fibers to inhibit postsurgical tumor recurrence and metastasis

Tumor-positive resection margins after surgery can result in tumor recurrence and metastasis. Although adjuvant postoperative radiotherapy and chemotherapy have been adopted in clinical practice, they lack efficacy and result in unavoidable side effects. Herein, a self-intensified in-situ therapy approach using electrospun fibers loaded with a biomimetic nanozyme and doxorubicin (DOX) is developed. The fabricated PEG-coated zeolite imidazole framework-67 (PZIF67) is demonstrated as a versatile nanozyme triggering reactions in cancer cells based on endogenous H₂O₂ and •O₂^-. The PZIF67-generated •OH induces reactive oxygen species (ROS) overload, implementing chemodynamic therapy (CDT). The O₂ produced by PZIF67 inhibits the expression of hypoxia-up-regulated proteins, thereby suppressing tumor progression. PZIF67 also catalyzes the degradation of glutathione, further disturbing the intracellular redox homeostasis and enhancing CDT. Furthermore, the introduced DOX not only kills cancer cells individually, but also replenishes the continuously consumed substrates for PZIF67-catalyzed reactions. The PZIF67-weakened drug resistance strengthens the cytotoxicity of DOX. The combined application of PZIF67 and DOX also suppresses metastasis-associated genes. Both in vitro and in vivo results demonstrate that the self-intensified synergy of PZIF67 and DOX on electrospun fibers efficiently prevents postsurgical tumor recurrence and metastasis, offering a feasible therapeutic regimen for operable malignant tumors.

The Dual Effect of 3D-Printed Biological Scaffolds Composed of Diverse Biomaterials in the Treatment of Bone Tumors

Bone tumors, including primary bone tumors, invasive bone tumors, metastatic bone tumors, and others, are one of the most clinical difficulties in orthopedics. Once these tumors have grown and developed in the bone system, they will interact with osteocytes and other environmental cells in the bone system's microenvironment, leading to the eventual damage of the bone's physical structure. Surgical procedures for bone tumors may result in permanent defects. The dual-efficacy of tissue regeneration and tumor treatment has made biomaterial scaffolds frequently used in treating bone tumors. 3D printing technology, also known as additive manufacturing or rapid printing prototype, is the transformation of 3D computer models into physical models through deposition, curing, and material fusion of successive layers. Adjustable shape, porosity/pore size, and other mechanical properties are an advantage of 3D-printed objects, unlike natural and synthetic material with fixed qualities. Researchers have demonstrated the significant role of diverse 3D-printed biological scaffolds in the treatment for bone tumors and the regeneration of bone tissue, and that they enhanced various performance of the products. Based on the characteristics of bone tumors, this review synthesized the findings of current researchers on the application of various 3D-printed biological scaffolds including bioceramic scaffold, metal alloy scaffold and nano-scaffold, in bone tumors and discussed the advantages, disadvantages, and future application prospects of various types of 3D-printed biological scaffolds. Finally, the future development trend of 3D-printed biological scaffolds in bone tumor is summarized, providing a theoretical foundation and a larger outlook for the use of biological scaffolds in the treatment of patients with bone tumors.

Enzyme-Enhanced Codelivery of Doxorubicin and Bcl-2 Inhibitor by Electrospun Nanofibers for Synergistic Inhibition of Prostate Cancer Recurrence

One of the great challenges of postoperative prostate cancer management is tumor recurrence. Although postoperative chemotherapy presents benefits to inhibit unexpected recurrence, it is still limited due to the drug resistance or intolerable complications of some patients. Electrospun nanofiber, as a promising drug carrier, demonstrating sustained drug release behavior, can be implanted into the tumor resection site during surgery and is conductive to tumor inhibition. Herein, we fabricated electrospun nanofibers loaded with doxorubicin (DOX) and ABT199 to synergistically prevent postoperative tumor recurrence. Enzymatic degradation of the biodegradable electrospun nanofibers facilitated the release of the two drugs. The primarily released DOX from the electrospun nanofibers effectively inhibited tumor recurrence. However, the sustained release of DOX led to drug resistance of the tumor cells, yielding unsatisfactory eradication of the residual tumor. Remarkably, the combined administration of DOX and ABT199, simultaneously released from the nanofibers, not only prolonged the chemotherapy by DOX but also overcame the drug resistance via inhibiting the Bcl-2 activation and thereby enhancing the apoptosis of tumor cells by ABT199. This dual-drug-loaded implant system, combining efficient chemotherapy and anti-drug resistance, offers a prospective strategy for the potent inhibition of postoperative tumor recurrence.