Biology subjects

Fujino, K.

Publications and source records attributed to Fujino, K..

5 recordsLinked to original sources

bioRxiv2026

Aptamer-Targeted PLGA Nanoparticles for Biofilm-Directed Intra-articular Antibiotic Delivery in Prosthetic Joint Infection

Introduction: Prosthetic joint infection (PJI) is a severe complication of orthopedic surgery, driven by biofilm-forming bacteria such as Staphylococcus aureus. Conventional antibiotics are limited in penetrating biofilms or remaining localized at the infection site. We engineered a targeted nanocarrier system by conjugating DNA aptamers specific to S. aureus biofilm components onto poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) encapsulating vancomycin. PLGA NPs were synthesized using flow-focusing microfluidics, followed by surface functionalization via EDC/NHS chemistry. Aptamer conjugation was validated using gel electrophoresis and DLS. Targeting efficiency and antimicrobial activity were evaluated through fluorescence microscopy, bacterial viability assays and in vitro biofilm models. Biodistribution and joint retention were assessed using fluorescent aptamer-conjugated NPs following intra-articular injection in rat knee joints. Results: The optimized vancomycin-loaded NPs exhibited uniform morphology, high vancomycin loading capacity (7.9 {+/-} 2.2%), and a sustained biphasic release profile with an early high-release phase followed by slower extended release. PK modeling indicated prolonged intra-articular drug retention with concentrations maintained above the minimum inhibitory concentration (MIC) for an extended period. Aptamer conjugation preserved nanoparticle stability and enhanced binding and retention within S. aureus biofilms in vitro, supporting improved biofilm localization. In-vivo fluorescence imaging demonstrated high local retention of aptamer-conjugated NPs, supporting localized joint retention with limited off-target tissue signal. Conclusions: S. aureus-specific aptamer conjugated nanoparticles (SA Apt-P(V)) represent a targeted intra-articular delivery platform with potential for localized PJI therapy. The combined in-vitro and in-vivo findings highlight their potential to improve local therapeutic concentration, minimize systemic exposure, and enhance infection control within prosthetic joints.

bioengineering↗

bioRxiv2026

Compartment-resolved in vivo phage display biopanning reveals constraint-driven peptide sequence landscapes

Previous in vivo phage display studies establish the value of the approach for identifying organ-homing and tissue-associated peptides, but whether recovered sequences form diffuse hit lists or structured repertoires remains unclear. This study combines systemic in vivo phage selection, laser-capture microdissection, and high-throughput sequencing to profile recoverable 7-mer peptide repertoires across 41 bulk organs, 39 capillary beds, and 125 parenchymal microenvironments. Across these anatomical scales, the repertoires show non-diffuse, compartment-dependent organization in enrichment-profile space, supported by robustness and null-model analyses. Compartment resolution provides information not apparent in bulk-organ profiles: representative motif-defined neighborhoods exhibit contrasting local sequence-tolerance regimes, ranging from bounded variation to near-single-sequence convergence. Compartment-resolved analysis also nominates EVGTARY, a cortex-associated candidate that is not prioritized by bulk-organ ranking. In an exploratory mouse-level analysis, an EVGTARY-conjugated branched polyethyleneimine (BPEI) polyplex is associated with increased cortical DsRed fluorescence compared with BPEI polyplex alone. Together, these findings shift the analytical unit of in vivo phage display from isolated organ-associated hits toward the organization of recoverable peptide repertoires and support an interpretation in which intact tissue context constrains the range of peptide solutions that remain recoverable after systemic in vivo phage selection.

molecular biology↗

bioRxiv2025

β-III tubulin identifies anti-fibrotic state of pericytes in pulmonary fibrosis

Pericytes have been implicated in pulmonary fibrosis, yet their activated cellular states and functional roles remain largely unclear. Here, we identified {beta}-III tubulin (Tuj1) as a distinctive marker for fibrosis-associated lung pericytes. Most pericytes in fibrotic regions are Tuj1-positive and interact uniquely with multiple endothelial cells, localizing near collagen-producing fibroblasts and pro-fibrotic SPP1+/arginase+ macrophages. Tuj1 expression is predominantly induced in pericytes during the fibrotic phase, and Tuj1 gene (Tubb3) knockout in mice exacerbates lung fibrosis, accompanied by an increase in the neighboring pro-fibrotic fibroblasts and macrophages, suggesting an anti-fibrotic role for Tuj1-expressing pericytes. Mechanistically, the anti-fibrotic chemokine CXCL10 is upregulated in Tuj1-expressing pericytes, whereas this upregulation is not observed in Tubb3 knockout. Moreover, CXCL10 inhibits the pro-fibrotic differentiation of macrophages induced by lung fibroblasts in culture, implying that CXCL10 may mediate the anti-fibrotic effects of Tuj1-expressing pericytes. These findings underscore the role of lung pericytes in negatively regulating fibrotic process and their potential as therapeutic targets for pulmonary fibrosis patients. SummaryIn response to fibrotic stimuli, lung pericytes upregulate {beta}-III tubulin (Tuj1) expression, adopting an anti-fibrotic phenotype. This phenotype acts as a negative immune regulator of pro-fibrotic macrophage differentiation by releasing CXCL10, thereby counteracting the progression of pulmonary fibrosis.

pathology↗

bioRxiv2022

Targeting the Hedgehog Signaling Pathway to Improve Tendon-to-Bone Integration

ObjectiveWhile the role of Hedgehog (Hh) signaling in promoting zonal fibrocartilage production during development is well-established, whether this pathway can be leveraged to improve tendon-to-bone repair in adults is unknown. Our objective was to genetically and pharmacologically stimulate the Hh pathway in cells that give rise to zonal fibrocartilaginous attachments to promote tendon-to-bone integration. DesignHh signaling was stimulated genetically, via constitutive Smo (SmoM2 construct) activation of activated bone marrow stromal cells, or pharmacologically, via systemic agonist delivery, to mice following anterior cruciate ligament reconstruction (ACLR). To assess tunnel integration, we measured mineralized fibrocartilage (MFC) formation in these mice 28 days post-surgery and performed tunnel pullout testing. ResultsHh pathway-related genes increased in cells forming the zonal attachments in WT mice. Both genetic and pharmacologic stimulation of the Hh pathway increased MFC formation and integration strength 28 days post-surgery. We next conducted studies to define the role of Hh in specific stages of the tunnel integration process. We found Hh agonist treatment increased proliferation of the progenitor pool in the first week post-surgery. Additionally, genetic stimulation led to continued MFC production in later stages of the integration process. These results indicate that Hh signaling plays an important biphasic role in cell proliferation and differentiation towards fibrochondrocytes following ACLR. ConclusionThis study reveals a biphasic role for Hh signaling during the tendon-to-bone integration process after ACLR. In addition, the Hh pathway is a promising therapeutic target to improve tendon-to-bone repair outcomes.

bioengineering↗

bioRxiv2019

Distinct transcriptional programs of SOX2 in different types of small cell lung cancers

SOX2 is an oncogene in human small cell lung cancer (SCLC), an aggressive neuroendocrine (NE) tumor. However, the roles of SOX2 in SCLC remain unclear, and strategies to selectively target SOX2 in SCLC cells have not yet been established. We herein demonstrated that SOX2 is involved in NE differentiation and tumorigenesis in cooperation with ASCL1, a lineage-specific transcriptional factor, in the classical subtype of SCLC cell lines. ASCL1 recruits SOX2, which promotes INSM1 expression. Precursor SCLC lesions were established in Trp53 (-/-); CCSPrtTA; tetOCre; floxedRb1; floxedHes1 mice, and the NE neoplasms induced were positive for Ascl1, Sox2, and Insm1. In contrast to the ASCL1-SOX2 signaling axis to control the SCLC phenotype in classical subtype SCLC, SOX2 targeted distinct genes, such as those related to the Hippo pathway, in ASCL1-negative, variant subtype SCLC. The present results support the importance of the ASCL1-SOX2 axis as a main subtype of SCLC, and suggest the therapeutic potential of targeting the ASCL1-SOX2 signaling axis and the clinical utility of SOX2 as a biological marker in the classical subtype of SCLC.

cancer biology↗