The stroma is a relevant player in driving and supporting the progression of pancreatic ductal adenocarcinoma (PDAC), and a large body of evidence highlights its role in hindering the efficacy of current therapies. In fact, the dense extracellular matrix (ECM) characterizing this tumor acts as a natural physical barrier, impairing drug penetration. Consequently, all of the approaches combining stroma-targeting and anticancer therapy constitute an appealing option for improving drug penetration. Several strategies have been adopted in order to target the PDAC stroma, such as the depletion of ECM components and the targeting of cancer-associated fibroblasts (CAFs), which are responsible for the increased matrix deposition in cancer. Additionally, the leaky and collapsing blood vessels characterizing the tumor might be normalized, thus restoring blood perfusion and allowing drug penetration. Even though many stroma-targeting strategies have reported disappointing results in clinical trials, the ECM offers a wide range of potential therapeutic targets that are now being investigated. The dense ECM might be bypassed by implementing nanoparticle-based systems or by using mesenchymal stem cells as drug carriers. The present review aims to provide an overview of the principal mechanisms involved in the ECM remodeling and of new promising therapeutic strategies for PDAC.

Human platelet lysate (hPL) is a pool of growth factors and cytokines able to induce regeneration of different tissues. Despite its good potentiality as therapeutic tool for regenerative medicine applications, hPL has been only moderately exploited in this field. A more widespread adoption has been limited because of its rapid degradation at room temperature that decreases its functionality. Another limiting factor for its extensive use is the difficulty of handling the hPL gels. In this work, silk fibroin-based patches were developed to address several points: improving the handling of hPL, enabling their delivery in a controlled manner and facilitating their storage by creating a device ready to use with expanded shelf life. Patches of fibroin loaded with hPL were synthesized by electrospinning to take advantage of the fibrous morphology. The release kinetics of the material was characterized and tuned through the control of fibroin crystallinity. Cell viability assays, performed with primary human dermal fibroblasts, demonstrated that fibroin is able to preserve the hPL biological activity and prolong its shelf-life. The strategy of storing and preserving small active molecules within a naturally-derived, protein-based fibrous scaffold was successfully implemented, leading to the design of a biocompatible device, which can potentially simplify the storage and the application of the hPL on a human patient, undergoing medical procedures such as surgery and wound care. Human platelets lysate (hPL) is a mixture of growth factors and cytokines able to induce the regeneration of damaged tissues. This study aims at enclosing hPL in a silk fibroin electrospun matrix to expand its utilization. Silk fibroin showed the ability to preserve the hPL activity at temperature up to 60 °C and the manipulation of fibroin's crystallinity provided a tool to modulate the hPL release kinetic. This entails the possibility to fabricate the hPL silk fibroin patches in advance and store them, resulting in an easy and fast accessibility and an expanded use of hPL for wound healing.

In the biomedical sector the availability of engineered scaffolds and dressings that control and reduce inflammatory states is highly desired, particularly for the management of burn wounds. In this work, we demonstrate for the first time, to the best of our knowledge, that electrospun fibrous dressings of poly(octyl cyanoacrylate) (POCA) combined with polypropylene fumarate (PPF) possess anti-inflammatory activity and promote the fast and effective healing of mild skin burns in an animal model. The fibers produced had an average diameter of (0.8 ± 0.1) µ m and they were able to provide a conformal coverage of the injured tissue. The application of the fibrous mats on the burned tissue effectively reduced around 80% of the levels of pro-inflammatory cytokines in the first 48 h in comparison with un-treated animals, and enhanced skin epithelialization. From histological analysis, the skin thickness of the animals treated with POCA : PPF dressings appeared similar to that of one of the naïve animals: (13.7 ± 1.4) µ m and (14.3 ± 2.5) µ m for naïve and treated animals, respectively. The density of dermal cells was comparable as well: (1100 ± 112) cells mm ⁻² and (1358 ± 255) cells mm ⁻² for naïve and treated mice, respectively. The results demonstrate the suitability of the electrospun dressings in accelerating and effectively promoting the burn healing process.

A water-based synthesis to produce micro and nano particles of keratin, that can be easily loaded with drugs and showed a sustained release, is reported. The particles interaction with mucin could be altered to favor or decrease their mucoadhesion.

The engraftment of transplanted islets depends on the rapid establishment of a novel vascular network. The present study evaluated the effects of cord blood-derived blood outgrowth endothelial cells (BOECs) on the viability of neonatal porcine islets (NPIs) and the post-transplant outcome of grafted NPIs. Dispersed NPIs and human BOECs were reaggregated on microwell cell culture plates and tested for their anti-apoptotic and pro-angiogenic capacity by qRT-PCR and immunohistochemistry. The in vivo functionality was analyzed after transplantation into diabetic NOD-SCID IL2rγ^−/− (NSG) mice. The spheroids, which contained reaggregated neonatal porcine islet cells (REPIs) and BOECs, exhibited enhanced viability and a significantly elevated gene expression of VEGFA, angiopoetin-1, heme oxygenase-1, and TNFAIP3 (A20) in vitro. The development of normoglycemia was significantly faster in animals transplanted with spheroids in comparison to the only REPI group (median 51.5 days versus 60 days) (p < 0.05). Furthermore, intragraft vascular density was substantially increased (p < 0.01). The co-transplantation of prevascularized REPI-BOEC spheroids resulted in superior angiogenesis and accelerated in vivo function. These findings may provide a novel tool to enhance the efficacy of porcine islet xenotransplantation.