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Biology subjects

Cruz, L. J.

Publications and source records attributed to Cruz, L. J..

3 recordsLinked to original sources

Spatial transcriptomics defines the mechanisms of hiPSC derived stem cell mediated repair in human articular cartilage

We here determined therapeutic efficacy and mode-of-action of human induced pluripotent-derived therapeutic stem cells (hiMSCs) across in vivo mouse and ex vivo human osteoarthritis models. hiMSC treatment in DMM-mice significantly reduced OARSI damage scores, which was affirmed by a decrease in the catabolic marker Mmp13 and an increase in the anabolic marker Col2. These treatment effects appeared, irrespective of modifying factors such as xeno-free media or thermosensitive hydrogel carrier. Subsequently treatment of hiMSC+gel in human osteoarthritic cartilage explants showed a transcriptome-wide significant activation of the cholesterol and sterol synthesis pathways marked by genes such as MVD, DHCR7, MSMO1, FABP3. Additionally, we showed that these changes alleviated OA-associated imbalances of the cellular Zinc-ion homeostasis pathways, represented by genes such as MT1F, MT1G, MT1H and SLC30A1. Spatial transcriptomics then sensitively captured that hiMSC+gel treatment evoked, specifically at the superficial cartilage layer, a consistent upregulation of healthy chondrocyte markers such as CHAD, ACAN, FRZB, and SOX9, alongside a suppression of catabolic and inflammatory mediators such as SERPINE1, SPP1, MMP13, ADAMTS5. Our findings link therapeutic outcomes of hiMSC treatment to precise spatially resolved molecular changes in human tissue, that would otherwise be obscured by heterogeneous cell populations. Collectively our study highlighted that hiPSC-derived stem cell therapy (hiMSCs) could provide a scalable off-the-shelf solution to treat osteoarthritis, with strong prospects for clinical applications in the near future.

developmental biology↗

Advancing Therapeutic Solutions: Poloxamer-based Thermosensitive Injectable Hydrogels containing a Self-assembling Peptide for In situ Gelation in an Osteoarthritis Murine Model

This study presents the development and characterization of a novel thermosensitive injectable hydrogel designed to enhance the biomechanical properties of poloxamer 407 (P407) through the incorporation of a self-assembling peptide. The primary objective was to engineer a formulation that rapidly gels following intra-articular (i.a.) injection, exhibits improved mechanical strength, and enables sustained release of embedded therapeutic cargo. Gelation time assays demonstrated that the P407-peptide formulation solidified more quickly than P407 alone at equivalent concentrations. Rheological analysis revealed a 1.5 kPa increase in storage modulus in the hybrid hydrogel, confirming improved mechanical integrity. In vitro biocompatibility was assessed using human chondrocytes, with MTS assays and LIVE/DEAD staining indicating no cytotoxicity across tested concentrations. To evaluate in vivo applicability, a near-infrared fluorescent (NIRF) dye was incorporated into the hydrogel and injected intra-articularly into an osteoarthritis (OA) mouse model. The labeled formulation allowed for successful tracking and demonstrated localized gelation, supporting its suitability for site-specific, sustained delivery. Overall, the P407-peptide hydrogel offers a promising platform for i.a. therapeutic applications, combining injectability, rapid thermoresponsive gelation, mechanical reinforcement, and controlled release behavior, making it well-suited for regenerative medicine and OA treatment.

biochemistry↗

Triplet-Triplet Annihilation PLGA-Nanoparticles for Cancer Bioimaging

Triplet-triplet annihilation upconversion (TTA-UC) nanoparticles (NPs) have emerged as imaging probes and therapeutic probes in recent years due to their excellent optical properties. In contrast to lanthanide ions-doped inorganic materials, highly efficient TTA-UC can be generated by low excitation power density, which makes it suitable for clinical applications. In the present study, we used biodegradable poly(lactic-co-glycolic acid) (PLGA)-NPs as delivery vehicle for TTA-UC based on the heavy metal porphyrin Platinum(II) octaethylporphyrin (PtOEP) and the polycyclic aromatic hydrocarbon 9,10-diphenylanthracene (DPA) as photosensitizer/emitter pair. TTA-UC-PLGA-NPs were successfully synthesized according to an oil-in-water emulsion and solvent evaporation method. After physicochemical characterization, UC-efficacy of TTA-UC-PLGA-NPs was assessed in vitro and ex vivo. TTA-UC could be detected in the tumor area 96 hours after in vivo administration of TTA-UC-PLGA-NPs, confirming the integrity and suitability of PLGA-NPs as TTA-UC in vivo delivery system. Thus, this study provides proof-of-concept that the advantageous properties of PLGA can be combined with the unique optical properties of TTA-UC for the development of advanced nanocarriers for simultaneous in vivo molecular imaging and drug delivery.

bioengineering↗