Collective cell migration plays a critical role in physiological and pathological processes such as development, wound healing, and metastasis. Numerous studies have demonstrated how various types of chemical, mechanical, and electrical cues dictate the collective migratory behaviors of cells. Although an acoustic cue can be advantageous because of its noninvasiveness and biocompatibility, cell migration in response to acoustic stimulation remains poorly understood. In this study, we developed a device that is able to apply surface acoustic waves to a cell culture substrate and investigated the effect of propagating acoustic waves on collective cell migration. The migration distance estimated at various wave intensities revealed that unidirectional cell migration was enhanced at a critical wave intensity and that it was suppressed as the intensity was further increased. The increased migration might be attributable to cell orientation alignment along the direction of the propagating wave, as characterized by nucleus shape. Thicker actin bundles indicative of a high traction force were observed in cells subjected to propagating acoustic waves at the critical intensity. Our device and technique can be useful for regulating cellular functions associated with cell migration.

Matrix stiffness, a critical physical property of the cellular environment, is implicated in epidermal homeostasis. In particular, matrix stiffening during the pathological progression of skin diseases appears to contribute to cellular responses of keratinocytes. However, it has not yet elucidated the molecular mechanism underlying matrix-stiffness-mediated signaling in coordination with chemical stimuli during inflammation and its effect on proinflammatory cytokine production. In this study, we demonstrated that keratinocytes adapt to matrix stiffening by increasing cell–matrix adhesion via actin cytoskeleton remodeling. Specifically, mechanosensing and signal transduction are coupled with chemical stimuli to regulate cytokine production, and interleukin-6 (IL-6) production is elevated in keratinocytes on stiffer substrates in response to 2,4-dinitrochlorobenzene. We demonstrated that β1 integrin and focal adhesion kinase (FAK) expression were enhanced with increasing stiffness and activation of ERK and the PI3K/Akt pathway was involved in stiffening-mediated IL-6 production. Collectively, our results reveal the critical role of matrix stiffening in modulating the proinflammatory response of keratinocytes, with important clinical implications for skin diseases accompanied by pathological matrix stiffening.

Recently, organoids have been widely used in cancer research. However, cancer organoids have limitation in reflecting physicochemical microenvironments of tumor. In particular, vascular networks not only provide oxygen and nutrients to the tumor, but also play an important role as a channel through which drugs move in cancer. Vascularization occurs in an uncontrollable form and speed in conventional methods. Here, we regulate the directionality of the vascular bed using the surface acoustic waves(SAW) technology by which, vascular cells are locally aligned. Aligned cells exhibited an improved, cell-cell contact enhancing the vascular system maturation in a couple days. Organoids are constructed from gastric cancer patients with four molecular subtypes according to TCGA. Organoids were dissociated into a single cell to make a co-culture spheroid with HUVEC cells. Co-cultured spheroids were formed by adding fibronectin according to the characteristics of the patient sample. The SAW device is built with interdigitated transducer, NiNbO3 substrate, polydimethylsiloxane(PDMS) and coverglass. After putting co-culture spheroids and HUVEC cells mixed with fibrin gel into the device, patterning is performed using surface acoustic waves with shaking in EGM-2 media. After fixing the models, CD31 and F-actin are stained and imaged through immunofluorescent. Immunohistochemistry was performed to confirm the blood vessel cross section. The blood vessels patterned with SAW were well aligned in a straight line, and a lumen structure was formed in a couple days. When co-cultured spheroids were used compared to mono-cultured spheroids, the interaction with external HUVECs was improved, allowing for efficient vascular organism models. As evidence for this, it was confirmed that HUVEC inside the co-cultured spheroid and HUVEC outside were connected through interaction when PKH dyeing was done in a different color. We showed that blood vessels are formed faster and thicker in patterning models than in random models, and interactions with co-cultured spheroids are also high. Through immunofluorescent staining, we found that the number of vascular branches linked to spheroids was higher in the SAW model. In addition, in the H&E results, it was confirmed that the blood vessels were arranged in a line, and that differentiation occurred appropriately to form a tubular structure. In addition, the number of blood formed inside the spheroid was higher. Currently, this model is used to test anti-cancer efficacy using FGFR inhibitors and ramucirumab in FGFR2-amplified patient-derived organoids. An efficient vascularized 3D cancer organoid model was constructed using acoustic waves. Our vascularized 3D cancer organoid research platform will be applied for specific drug screening platform that directly aid the treatment of the specific patients with various drugs including chemoagents, targeted drugs, and immune checkpoints inhibitors. Citation Format: Hyoyoung Kim, Yunam Lee, Byungjun Kang, Un-Jung Yun, Yunjung Choi, So Hui Kim, Hyunki Kim, Hyungsuk Lee, Minkyu Jung. Vascularized 3D cancer organoid research platform using surface acoustic waves [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 159.

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Selective retinal therapy (SRT) employs a micro-second short-pulse lasers to induce localized destruction of the targeted retinal structures with a pulse duration and power aimed at minimal damage to other healthy retinal cells. SRT has demonstrated a great promise in the treatment of retinal diseases, but pulse energy thresholds for effective SRT procedures should be determined precisely and in real time, as the thresholds could vary with disease status and patients. In this study, we present the use of a multi-port fiber-based interferometer (MFI) for highly sensitive real-time SRT monitoring. We exploit distinct phase differences among the fiber ports in the MFI to quantitatively measure localized fluctuations of complex-valued information during the SRT procedure. We evaluate several metrics that can be computed from the full complex-valued information and demonstrate that the complex contour integration is highly sensitive and most correlative to pulse energies, acoustic outputs, and cell deaths. The validity of our method was demonstrated on excised porcine retinas, with a sensitivity and specificity of 0.92 and 0.88, respectively, as compared with the results from a cell viability assay.