Hydrogel scaffolds blends to host Spheroids from human adipose stem cells

INTRODUCTION Adipose stem cells represent a reliable source of stem cells for their widely demonstrated potential in regenerative medicine and tissue engineering applications. New recent insights show that 3D models may properly mimic the native tissue properties; in fact Spheroids from Adipose derived Stem Cells (S-ASCs) displayed enhanced regenerative abilities if compared to 2D models. Stem cell therapy success is determined by "cell-quality" thus the involvement of stress signals and cellular aging need to be deeply investigated. The development of 3D cell-laden hydrogels has enabled to mimic the peculiar scenario of a native tissue. We studied SASCs-cell quality and tested their viabil…

Hydrogel scaffolds based on k-Carrageenan/xyloglucan blends to host spheroids from human adipose stem cells

Hydrogels are water-swollen networks of hydrophilic polymer. They can be fabricated in various shapes and swell in water or aqueous solutions maintaining their original shape or undergo progressive erosion; can exibit large volume phase transitions with the change of one environmental parameter (stimuli-responsivness), shock absorption and low sliding friction properties (1). The morphology and mechanical properties of hydrogels are strongly affected by the network composition, the nature and degree of crosslinking and the degree of swelling. Indeed, when hydrogels are designed as scaffolds for human tissues remodeling, they must have sufficient mechanical integrity to provide support to th…

Idrogeli a base di xiloglucano e k-carragene con sferoidi di cellule staminali adipose umane come scaffolds per la medicina rigenerativa

Con l’obiettivo di sviluppare scaffold per la rigenerazione dei tessuti umani con sferoidi di cellule staminali adipose (S-ASC), questo lavoro indaga le proprietà degli idrogeli formati da dei polisaccaridi che subiscono transizioni sol-gel indotte dalla temperatura e le loro miscele: k-carragene (k-C) e xiloglucano parzialmente degalattosilato (Deg-XG). Gli idrogeli sono network polimerici idrofili rigonfiati dall'acqua. La morfologia e le proprietà meccaniche degli idrogeli sono fortemente influenzate dalla loro composizione, grado di reticolazione e di rigonfiamento. Quando sono progettati come scaffold, devono avere sufficiente integrità meccanica per fornire supporto alle cellule, dall…

Adipose stem cell spheroids-laden hydrogels for minimally invasive bone and cartilage regeneration interventions

Agarose/k-Carrageenan-based hydrogel films enriched with natural extracts for wound healing applications

Hydrogels are 3D hydrophilic networks that can hold significant amounts of water within their structure, without dissolving in water.

Radiation engineered nanogels as platforms for medical diagnostics and therapeutic nanodevices

A scalable, single step, synthetic approach for the manufacture of biocompatible, functionalized microgels and nanogels has been developed. Pulsed EB irradiation of PVP aqueous solutions, at relatively low energies per pulse and doses within the sterilization dose range, has led to a variety of ‘as-born’ sterile, functional nanostructures that exhibit a combination of favourable properties which make them suitable as biomedical nanocarriers. Reactive functional groups have been generated by graft copolymerization of functional acrylic monomers. These groups can be used to attach fluorescent probes to the NPs, to bioconjugate ligands of specific cell receptors and to incorporate therapeutics…

Miscele di k-carragenina e PVA come bio-inchiostri per stampa 3D di scaffold per la ricostruzione della cartilagine

Introduzione La k-carragenina (kC) è un poligalattano solfato ottenuto da alghe rosse con un contenuto di estere-solfato dal 25 al 30% e una peso molecolare medio ben superiore a 100 kDa. È formato da unità alternate di D-galattosio e 3,6-anidro-galattosio (3,6-AG) unite da legami α-1,3 e β-1,4-glicosidici. [1] Il kC assomiglia ai glicosaminoglicani (GAG) che sono i costituenti centrali dei tessuti connettivi, può essere quindi studiato per produrre scaffold per l'ingegneria tissutale. Il kC è solubile in acqua a temperature superiori a 60 °C e può formare gel stabili raffreddandosi. Le reti di kC sono forti, fragili e l'assenza di porosità interconnesse può limitare la colonizzazione dell'…

Idrogeli con sferoidi di cellule staminali adipose per interventi mini-invasivi di rigenerazione ossea o cartilaginea

Introduzione Lo xiloglucano (XG) è un polisaccaride sia di struttura che di riserva, perché svolge il ruolo di matrice nelle pareti cellulari delle piante superiori ma è anche presente in alcuni semi, tra i quali tamarindo. Lo xiloglucano da semi di tamarindo è disponibile in commercio, è un polimero biocompatibile, approvato dalla FDA per uso alimentare. È caratterizzato da uno scheletro di β-(1, 4)-D-glucano parzialmente sostituito da α-(1, 6)-D-xilosio e β-(1, 2)-D-galattossilosio. La scissione enzimatica di alcuni dei residui di galattosio fornisce allo XG proprietà di gelificazione indotte da variazioni di temperatura. In particolare, quando viene rimosso il 35% circa dei residui di ga…

Agarose/k-Carrageenan-based hydrogel films enriched with natural extracts for wound healing applications

Hydrogels are 3D hydrophilic networks that can hold significant amounts of water within their structure, without dissolving in water. They can offer a combination of favorable properties, including high absorbency of biological fluids, biocompatibility, biodegradability, stimuli-responsiveness, high storage capacity and release ability of small and large therapeutic molecules. The hydrogel films designed for wound dressing may accomplish several functions, playing an important role in the healing processes. They can absorb and retain the wound exudates, stimulating fibroblast proliferation and keratinocyte migration and promoting re-epithelialization. Furthermore, they can incorporate and r…

Exploring nose-to-brain insulin delivery as a new strategy for the treatment of Alzheimer’s disease

A growing body of evidence shows that Insulin, Insulin Receptor (IR) and IR signaling are involved in brain cognitive functions and their dysfunction is implicated in Alzheimer’s disease (AD) degeneration. Thus, administration of insulin could be a strategy for AD treatment. For this aim we designed, synthesized and characterized a nanogel system (NG) to deliver insulin to the brain, as a tool for the development of a new therapy for AD. A carboxyl-functionalized poly(N-vinyl pyrrolidone) nanogel system produced by high energy ionizing radiation was chosen as substrate for the covalent attachment of insulin or fluorescent molecules, relevant for its tracing

Injectable hydrogel formulations to host adipose stem cell spheroids for stemness maintenance and bone and cartilage regeneration

Adipose-derived mesenchymal stem cells (ASCs) represent a great promise for tissue regeneration as fat is a very abundant source of stem cells (1) and owing to their ability to self-renew and differentiate into specific tissue types (2). In general, they are usually cultured as two-dimensional (2D) adherent monolayers, not representative of the in vivo condition, often entailing lower cell viability and, more in general, a lower “cell quality” in terms of regenerative potential (3, 4). When ASCs are cultured in low adhesion flasks and with a suitable culture medium, they aggregate in the form of three-dimensional spheroids (SASCs). The incorporation of these spheroids into injectable, in-si…

k-Carrageenan and PVA blends as 3D printing bioinks for cartilage reconstruction scaffolding