Amnion-Derived Teno-Inductive Secretomes: A Novel Approach to Foster Tendon Differentiation and Regeneration in an Ovine Model

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Tendon injuries are at the frontier of innovative approaches to public health concerns and sectoral policy objectives. Indeed, these injuries remain difficult to manage due to tendon’s poor healing ability ascribable to a hypo-cellularity and low vascularity, leading to the formation of a fibrotic tissue affecting its functionality. Tissue engineering represents a promising solution for the regeneration of damaged tendons with the aim to stimulate tissue regeneration or to produce functional implantable biomaterials. However, any technological advancement must take into consideration the role of the immune system in tissue regeneration and the potential of biomaterial scaffolds to control the immune signaling, creating a pro-regenerative environment. In this context, immunoengineering has emerged as a new discipline, developing innovative strategies for tendon injuries. It aims at designing scaffolds, in combination with engineered bioactive molecules and/or stem cells, able to modulate the interaction between the transplanted biomaterial-scaffold and the host tissue allowing a pro-regenerative immune response, therefore hindering fibrosis occurrence at the injury site and guiding tendon regeneration. Thus, this review is aimed at giving an overview on the role exerted from different tissue engineering actors in leading immunoregeneration by crosstalking with stem and immune cells to generate new paradigms in designing regenerative medicine approaches for tendon injuries.

Section: Scaffold Immunoengineering Strategies For Tendon Te Applicationsmentioning

confidence: 99%

Scaffold-Mediated Immunoengineering as Innovative Strategy for Tendon Regeneration

Russo

Khatib

Prencipe

et al. 2022

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“…Total RNA from oAECs untreated (CTR) and treated with different doses of CoCl2 were extracted with TriReagent (Sigma-Aldrich, St. Louis, MO, USA), according to our previous reports [23,31,33]. Quantification of total RNA samples was assessed using Thermo Scientific NanoDrop 2000c UV-Vis spectrophotometer at 260 nm.…”

Section: Influence Of Chemical-induced Hypoxia On Oaec Genes' Expressionmentioning

confidence: 99%

“…In this context, previous works have reported that AECs under 20% O2 spontaneously reduce the pluripotent expression genes [10] and go into epithelial-to-mesenchymal transition (EMT) [31,32]. On the other hand, 2% O2 culture conditions positively affect AECs' differentiation towards the tenogenic lineage, inducing the up-regulation of tenogenic markers and improving the formation of tendon-like structures [33]. However, no studies to date have demonstrated the existence of a clear correlation between in vitro O2 tension and AEC biology, even if in vitro hypoxia might potentially be exploited to preserve or enhance positive therapeutic cell features.…”

Section: Introductionmentioning

confidence: 96%

Hypoxia-Mimetic CoCl2 Agent Enhances Pro-Angiogenic Activities in Ovine Amniotic Epithelial Cells-Derived Conditioned Medium

Mattia

Mauro

Monache

et al. 2022

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Amniotic epithelial stem cells (AECs) are largely studied for their pro-regenerative properties. However, it remains undetermined if low oxygen (O2) levels that AECs experience in vivo can be of value in maintaining their biological properties after isolation. To this aim, the present study has been designed to evaluate the effects of a hypoxia-mimetic agent, cobalt chloride (CoCl2), on AECs’ stemness and angiogenic activities. First, a CoCl2 dose-effect was performed to select the concentration able to induce hypoxia, through HIF-1α stabilization, without promoting any cytotoxicity effect assessed through the analysis of cell vitality, proliferation, and apoptotic-related events. Then, the identified CoCl2 dose was evaluated on the expression and angiogenic properties of AECs’ stemness markers (OCT-4, NANOG, SOX-2) by analysing VEGF expression, angiogenic chemokines’ profiles, and AEC-derived conditioned media activity through an in vitro angiogenic xeno-assay. Results demonstrated that AECs are sensitive to the cytotoxicity effects of CoCl2. The unique concentration leading to HIF-1α stabilization and nuclear translocation was 10 µM, preserving cell viability and proliferation up to 48 h. CoCl2 exposure did not modulate stemness markers in AECs while progressively decreasing VEGF expression. On the contrary, CoCl2 treatment promoted a significant short-term release of angiogenic chemokines in culture media (CM). The enrichment in bio-active factors was confirmed by the ability of CoCl2-derived CM to induce HUVEC growth and the cells’ organization in tubule-like structures. These findings demonstrate that an appropriate dose of CoCl2 can be adopted as a hypoxia-mimetic agent in AECs. The short-term, chemical-induced hypoxic condition can be targeted to enhance AECs’ pro-angiogenic properties by providing a novel approach for stem cell-free therapy protocols.

“…ImageJ software (NIH) was used to calculate the average fiber diameter size and pore size using at least 100 fibers, randomly chosen for each sample, as well as the angle distribution of the electrospun fibers using the Directionality plugin (n = 3 for each sample/time point). This plugin chops the image into square pieces and computes their Fourier power spectra, allowing the generation of statistics on the basis of the highest peak found, represented by the center of the Gaussian (direction), the standard deviation of the Gaussian (dispersion), and the goodness of the fit, where 1 is good, and 0 is bad [13,52]. The ha-PLGA scaffolds subjected to degradation were analyzed at 0, 1, 10, and 20 weeks.…”

Section: Scanning Electron Microscopy (Sem)mentioning

confidence: 99%

Amniotic Epithelial Stem Cells Counteract Acidic Degradation By-Products of Electrospun PLGA Scaffold by Improving Their Immunomodulatory Profile In Vitro

Khatib

Russo

Prencipe

et al. 2021

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Electrospun poly(lactic-co-glycolic acid) (PLGA) scaffolds with highly aligned fibers (ha-PLGA) represent promising materials in the field of tendon tissue engineering (TE) due to their characteristics in mimicking fibrous extracellular matrix (ECM) of tendon native tissue. Among these properties, scaffold biodegradability must be controlled allowing its replacement by a neo-formed native tendon tissue in a controlled manner. In this study, ha-PLGA were subjected to hydrolytic degradation up to 20 weeks, under di-H2O and PBS conditions according to ISO 10993-13:2010. These were then characterized for their physical, morphological, and mechanical features. In vitro cytotoxicity tests were conducted on ovine amniotic epithelial stem cells (oAECs), up to 7 days, to assess the effect of non-buffered and buffered PLGA by-products at different concentrations on cell viability and their stimuli on oAECs’ immunomodulatory properties. The ha-PLGA scaffolds degraded slowly as evidenced by a slight decrease in mass loss (14%) and average molecular weight (35%), with estimated degradation half-time of about 40 weeks under di-H2O. The ultrastructure morphology of the scaffolds showed no significant fiber degradation even after 20 weeks, but alteration of fiber alignment was already evident at week 1. Moreover, mechanical properties decreased throughout the degradation times under wet as well as dry PBS conditions. The influence of acid degradation media on oAECs was dose-dependent, with a considerable effect at 7 days’ culture point. This effect was notably reduced by using buffered media. To a certain level, cells were able to compensate the generated inflammation-like microenvironment by upregulating IL-10 gene expression and favoring an anti-inflammatory rather than pro-inflammatory response. These in vitro results are essential to better understand the degradation behavior of ha-PLGA in vivo and the effect of their degradation by-products on affecting cell performance. Indeed, buffering the degradation milieu could represent a promising strategy to balance scaffold degradation. These findings give good hope with reference to the in vivo condition characterized by physiological buffering systems.