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Surgery with the assistance of conventional radiotherapy, chemotherapy and immunotherapy is the basis for head and neck squamous cell carcinoma (HNSCC) treatment. However, with these treatment modalities, the recurrence and metastasis of tumors remain at a high level. Increasingly, the evidence indicates an excellent anti-tumor effect of chimeric antigen receptor T (CAR-T) cells in hematological malignancy treatment, and this novel immunotherapy has attracted researchers' attention in HNSCC treatment. Although several clinical trials have been conducted, the weak anti-tumor effect and the side effects of CAR-T cell therapy against HNSCC are barriers to clinical translation. The limited choices of targeting proteins, the barriers of CAR-T cell infiltration into targeted tumors and short survival time in vivo should be solved. In this review, we introduce barriers of CAR-T cell therapy in HNSCC. The limitations and current promising strategies to overcome barriers in solid tumors, as well as the applications for HNSCC treatment, are covered. The perspectives of CAR-T cell therapy in future HNSCC treatment are also discussed. [ABSTRACT FROM AUTHOR]

A microdevice that offers glucagon supplements in a safe, non‐invasive, and glucose‐responsive manner is ideal for avoiding fatal hypoglycemia consequences from insulin overdosage during daily diabetes treatment. However, mold‐assisted microfabrication of biomedical materials or devices typically needs high‐resolution laser ablation to scale down structural design. In addition, the majority of the polymeric drug delivery materials being used to fabricate devices are dissolvable or deformable in aqueous environments, which restricts washing‐based cleaning and purification procedures post shape fixation. This study leverages the design flexibility of 3D printing‐assisted mold casting and presents a shrinking microfabrication approach that allows subsequent washing procedures to remove toxic monomer residues during polymerization. The feasibility of this approach is demonstrated by developing a glucose‐responsive transdermal glucagon microneedle patch through matrix volume change‐mediated release kinetic control. Shown in the type 1 diabetic mouse model, this transdermal patch can reverse the occurrence of hypoglycemia while lowering the risk of monomer residue‐induced irritation during treatment. Freeing from the restrain of molding resolution for microstructure design, this shrinking methodology further provides an insight into post‐fabrication purifications of biomedical materials. [ABSTRACT FROM AUTHOR]

Chimeric antigen receptor (CAR) T cells exhibit promising results for cancer immunotherapy. However, the clinical success is still restricted to certain types of blood cancers, while in solid tumors the clinical activity is modest and potential toxicities remain a concern. There are various barriers that prevent CAR T cells from combating solid tumors. Therefore, distinct strategies have been explored to augment CAR T cell proliferative capacity, persistence, and effector function. Altering the tumor microenvironment, and in particular its physiochemical properties and immunosuppressive milieu, is of great significance to facilitate CAR T cell therapy. In this article, emerging strategies implemented to overcome the barriers of CAR T cell therapy in solid tumors are reviewed. Enhancing infiltration, activation, and persistence of CAR T cells has been addressed in several preclinical models. The future development of this field to promote innovation and clinical translation is also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Advanced optical fibers and photonic structures play important roles in neuroscience research, along with recent progresses of genetically encoded optical actuators and indicators. Most techniques for optical neural implants rely on fused silica or long‐lasting polymeric fiber structures. In this paper, implantable and biodegradable optical fibers based on poly( l‐lactic acid) (PLLA) are presented. PLLA fibers with dimensions similar to standard silica fibers are constructed using a simple thermal drawing process at around 220 °C. The formed PLLA fibers exhibit high mechanical flexibility and optical transparency, and their structural evolution and optical property changes are systematically studied during in vitro degradation. In addition, their biocompatibility with brain tissues is evaluated in living mice, and full in vivo degradation is demonstrated. Finally, PLLA fibers are implemented as a tool for intracranial light delivery and detection, realizing deep brain fluorescence sensing and optogenetic interrogation in vivo. The presented materials and device platform offer paths to fully biocompatible and bioresorbable photonic systems for biomedical uses. [ABSTRACT FROM AUTHOR]

Tumor‐associated adipocytes (TAAs) recruit monocytes and promote their differentiation into tumor‐associated macrophages (TAMs) that support tumor development. Here, TAAs are engineered to promote the polarization of TAMs to the tumor suppressive M1 phenotype. Telratolimod, a toll‐like receptor 7/8 agonist, is loaded into the lipid droplets of adipocytes to be released at the tumor site upon tumor cell‐triggered lipolysis. Locally administered drug‐loaded adipocytes increased tumor suppressive M1 macrophages in both primary and distant tumors and suppressed tumor growth in a melanoma model. Furthermore, drug‐loaded adipocytes improved CD8+ T cell‐mediated immune responses within the tumor microenvironment and favored dendritic cell maturation in the tumor draining lymph nodes. [ABSTRACT FROM AUTHOR]

Photobiomodulation (PBM) has recently started to gain popularity in clinical therapeutics. Visible light, in particular, plays a critical role in osteogenesis modulation. However, the limited penetration depth of visible light in biological tissues has constrained the application of this technology in vivo. Herein a green light‐based PBM technique with implantable and biodegradable poly(L‐lactic acid) & poly(L‐actic‐co‐glycolic acid) optical fibers to achieve accelerated bone regeneration is explored. Facilitated with experimental characterizations as well as numerical simulations, optical and thermal behaviors of fibers operated in the biological environment are understood. The optical regulation of bone regeneration is systematically studied both in vitro and in vivo. Under green light irradiation, biochemical activities of bone marrow‐derived mesenchymal stem cells and their expression of osteogenic‐related factors are significantly elevated. By introducing green light into defective bone structures via fibers in a rodent model, the process of bone regeneration and repair is accelerated. Furthermore, fibers exhibit ideal biocompatibility with both cultured cells and living tissues and undergo complete degradation in vivo after ≈1 month. Assisted with degradable optical materials and devices, such as photobiomodulation technique provides a promising solution to tissue regeneration in various biomedical applications. [ABSTRACT FROM AUTHOR]

Optical fibers and waveguides in general effectively control and modulate light propagation, and these tools have been extensively used in communication, lighting and sensing. Recently, they have received increasing attention in biomedical applications. By delivering light into deep tissue via these devices, novel applications including biological sensing, stimulation and therapy can be realized. Therefore, implantable fibers and waveguides in biocompatible formats with versatile functionalities are highly desirable. In this review, we provide an overview of recent progress in the exploration of advanced optical fibers and waveguides for biomedical applications. Specifically, we highlight novel materials design and fabrication strategies to form implantable fibers and waveguides. Furthermore, their applications in various biomedical fields such as light therapy, optogenetics, fluorescence sensing and imaging are discussed. We believe that these newly developed fiber and waveguide based devices play a crucial role in advanced optical biointerfaces. [ABSTRACT FROM AUTHOR]