The differentiated cells can regenerate or repair damaged tissues, allowing lost functions caused by defective cells to be regained. [2] Therefore, supplying stem cells represents a potentially effective next-generation treatment to cure or prevent a number of diseases, including neurodegeneration, diabetes, arthritis, among others. However, conventional stem cell therapy delivery systems, such as intravenous injection and surgical implantation, show side effects and limitations, such as low delivery efficacy, inappropriate stem cell migration, hemorrhage, infection, and systemic exposure of cells. [3] Minimally invasive and targeted precise delivery systems would improve the efficacy of stem cell therapy and reduce side effects by allowing the efficient use of stem cells. [4] Magnetically powered microrobots have great potential for targeted therapy because these devices can be remotely controlled at small scales with high precision. [5] Several types of microrobots have been reported and shown to have the potential to accurately deliver various therapeutic agents to the target area using an external magnetic field. [5g,6] A number of 3D helical and spherical microrobots were fabricated by 3D laser lithography and metal deposition processes to A great deal of research has focused on small-scale robots for biomedical applications and minimally invasive delivery of therapeutics (e.g., cells, drugs, and genes) to a target area. Conventional fabrication methods, such as two-photon polymerization, can be used to build sophisticated micro-and nanorobots, but the long fabrication cycle for a single microrobot has limited its practical use. This study proposes a biodegradable spherical gelatin methacrylate (GelMA) microrobot for mass production in a microfluidic channel. The proposed microrobot is fabricated in a flow-focusing droplet generator by shearing a mixture of GelMA, photoinitiator, and superparamagnetic iron oxide nanoparticles (SPIONs) with a mixture of oil and surfactant. Human nasal turbinate stem cells (hNTSCs) are loaded on the GelMA microrobot, and the hNTSC-loaded microrobot shows precise rolling motion in response to an external rotating magnetic field. The microrobot is enzymatically degraded by collagenase, and released hNTSCs are proliferated and differentiated into neuronal cells. In addition, the feasibility of the GelMA microrobot as a cell therapeutic delivery system is investigated by measuring electrophysiological activity on a multielectrode array. Such a versatile and fully biodegradable microrobot has the potential for targeted stem cell delivery, proliferation, and differentiation for stem cell-based therapy.

Periodontitis is initiated by causative bacteria in the gingival sulcus. However, as the lesion is often deep and out of circulation system and biofilm is frequently formed on the bacteria cluster, use of antibacterial agents has been limited and the invasive method such as curettage is thought as an only treatment. Here we designed non-invasive photodynamic therapy (PDT), with the ointment which leads a photosensitizer deliverable into gingival sulcus. We assessed whether 650 nm light-emitting-diode (LED) penetrates the 3-mm soft tissue and effectively activates a photosensitizer toluidine-blue-O (TBO) through the thickness to remove Porphyromonas gingivalis and Fusobacterium nucleatum species. The oral ointment formulation was optimized to efficiently deliver the photosensitizer into gingival sulcus and its efficacy of PDT was evaluated in in vitro and in vivo models. Four weeks of TBO-formulation mediated-PDT treatment significantly attenuated periodontitis-induced alveolar bone loss and inflammatory cytokines production in rats. These results confirm that a 650 nm LED indeed penetrates the gingiva and activates our TBO formulation which is sufficiently delivered to, and retained within, the gingival sulcus; thus, it effectively kills the bacteria that reside around the gingival sulcus. Collectively, TBO-mediated PDT using LED irradiation has potential as a safe adjunctive procedure for periodontitis treatment.

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The SAVMs presented with diverse neurological deficits, including myelopathy. Endovascular or surgical treatment of SAVMs can result in good clinical outcomes in most patients.

The new PSMS grading system for patients with VCM correlated well with the previously used systems and included pain evaluation. This new grading system is an easy tool for the evaluation and comparison of outcomes before and after endovascular treatment.