Biology subjects

Rezzola, S.

Publications and source records attributed to Rezzola, S..

4 recordsLinked to original sources

bioRxiv2026

The hydrocup: a hollow electrospun scaffold for in vivo hydrogel-laden cell delivery

For regenerative medicine applications, transplanted cells are difficult to retain in a specific place to maximize the localized release of cytokines, which can positively modulate immune responses, angiogenesis and tissue regeneration. Here, we developed a hollow electrospun (ESP) scaffold with one open and one closed end to enclose a hydrogel laden with human mesenchymal stem cells (hMSCs); we termed this combination the hydrocup. hMSCs remained viable for 28 days in vitro and released functional cytokines similar to hMSCs in transplanted but non-enclosed hydrogels. The hydrocups remained intact and fixed in place for 6 weeks after subcutaneous implantation in rats, demonstrating in vivo compatibility. These results demonstrate that the hydrocup is the first, to our knowledge, cell-laden hydrogel delivery scaffold. This innovation could be developed for a wide variety of cell-based cytokine secretion or drug-laden hydrogel applications.

bioengineering↗

bioRxiv2021

Tumor-Antagonizing Fibroblasts Secrete Prolargin as Tumor Suppressor in Hepatocellular Carcinoma

Systemic treatment of hepatocellular carcinoma (HCC) targets the tumor microenvironment (TME) by combining immunotherapy with angiogenesis inhibitors. Cancer-associated fibroblasts (CAF) are important components of the TME, however their targeting in clinics remains challenging. To this end, the existence of tumor supressing CAF and their poor characterisation is a major conundrum. Starting from proteomics and single cell analysis, we outline CAF heterogeneity in HCC and describe a subtype of CAF that express a novel tumor-related protein prolargin. Upon secretion prolargin is deposited in the TME where its levels positively correlate with patient outcome (HR=0.37; p=0.01). In vivo, tumors with lower prolargin expression display faster progression (5-fold; p=0.01) and stronger angiogenesis. Mechanistically, aggressive HCC cells degrade prolargin using matrix metalloprotease 3 (MMP3). We show that prolargin binds and inhibits several growth factors, key to tumor progression. Inhibiting prolargin degradation combined with sorafenib, demonstrated superior tumor control compared to sorafenib treatment alone. In conclusion, prolargin-expressing CAF have tumor-antagonizing properties. Stabilizing prolargin tumoral levels should be considered for systemic therapy of HCC, involving CAF in existing TME targeting.

cancer biology↗

bioRxiv2020

Full cell infiltration and thick tissue formation in vivo in tailored electrospun scaffolds

Electrospun (ESP) scaffolds are a promising type of tissue engineering constructs for large defects with limited depth. To form new functional tissue, the scaffolds need to be infiltrated with cells, which will deposit extracellular matrix. However, due to dense fiber packing and small pores, cell and tissue infiltration of ESP scaffolds is limited. Here, we combine two established methods, increasing fiber diameter and co-spinning sacrificial fibers, to create a porous ESP scaffold that allows robust tissue infiltration. Full cell infiltration across 2 mm thick scaffolds is seen 3 weeks after subcutaneous implantation in rats. After 6 weeks, the ESP scaffolds are almost fully filled with de novo tissue. Cell infiltration and tissue formation in vivo in this thickness has not been previously achieved. In addition, we propose a novel method for in vitro cell seeding to improve cell infiltration and a model to study 3D migration through a fibrous mesh. This easy approach to facilitate cell infiltration further improves previous efforts and could greatly aid tissue engineering approaches utilizing ESP scaffolds. Statement of significanceElectrospinning creates highly porous scaffolds with nano- to micrometer sized fibers and are a promising candidate for a variety of tissue engineering applications. However, smaller fibers also create small pores which are difficult for cells to penetrate, restricting cells to the top layers of the scaffolds. Here, we have improved the cell infiltration by optimizing fiber diameter and by co-spinning a sacrificial polymer. We developed novel culture technique that can be used to improve cell seeding and to study cytokine driven 3D migration through fibrous meshes. After subcutaneous implantation, infiltration of tissue and cells was observed up to throughout up to 2 mm thick scaffolds. This depth of infiltration in vivo had not yet been reported for electrospun scaffolds. The scaffolds we present here can be used for in vitro studies of migration, and for tissue engineering in defects with a large surface area and limited depth.

bioengineering↗

bioRxiv2019

Mechanosensitive regulation of FGFR1 through the MRTF-SRF pathway

Controlling basic fibroblast growth factor (bFGF) signaling is important for both tissue-engineering purposes, controlling proliferation and differentiation potential, and for cancer biology, influencing tumor progression and metastasis. Here, we observed that human mesenchymal stromal cells (hMSCs) no longer responded to soluble or covalently bound bFGF when cultured on microfibrillar substrates, while fibroblasts did. This correlated with a downregulation of FGF receptor 1 (FGFR1) expression of hMSCs on microfibrillar substrates, compared to hMSCs on conventional tissue culture plastic (TCP). hMSCs also expressed less SRF on ESP scaffolds, compared to TCP, while fibroblasts maintained high FGFR1 and SRF expression. Inhibition of actin-myosin tension or the MRTF/SRF pathway decreased FGFR1 expression in hMSCs, fibroblasts and MG63 osteosarcoma cells. This downregulation was functional, as hMSCs became irresponsive to bFGF in the presence of MRTF/SRF inhibitor. Together, our data show that hMSCs, but not fibroblasts, are irresponsive to bFGF when cultured on microfibrillar susbtrates by downregulation of FGFR1 through the MRTF/SRF pathway. This is the first time FGFR1 expression has been shown to be mechanosensitive and adds to the sparse literature on FGFR1 regulation. These results could open up new targets for cancer treatments and could aid designing tissue engineering constructs that better control cell proliferation.

bioengineering↗