Comparison of the characteristics of canine adipose tissue-derived mesenchymal stem cells extracted from different sites and at different passage numbers

Mesenchymal stem cells (MSCs) have desirable characteristics for use in therapy in animal models and veterinary medicine, due to their capacity of inducing tissue regeneration and immunomodulation. The objective of this study was to evaluate the differences between canine adipose tissue-derived MSCs (AD-MSCs) extracted from subcutaneous (Sc) and visceral (Vs) sites. Surface antigenic markers, in vitro differentiation, and mineralized matrix quantification of AD-MSCs at different passages (P₄, P₆, and P₈) were studied. Immunophenotypic analysis showed that AD-MSCs from both sites were CD44+, CD90+, and CD45−. Moreover, they were able, in vitro, to differentiate into fat, cartilage, and bone. Sc-AD-MSCs preserve in vitro multipotentiality up to P₈, but Vs-AD-MSCs only tri-differentiated up to P₄. In addition, compared to Vs-AD-MSCs, Sc-AD-MSCs had greater capacity for in vitro mineralized matrix synthesis. In conclusion, Sc-AD-MSCs have advantages over Vs-AD-MSCs, as Sc AD-MSCs preserve multipotentiality during a greater number of passages, have more osteogenic potential, and require less invasive extraction.

Preparation of pellets containing Pothomorphe umbellata extracts by extrusion-spheronization: improvement of 4-nerolidylcatechol photostability

Pothomorphe umbellata (L.) Miq., Piperaceae, has been extensively used in Brazilian folk medicine and it is well known for its strong antioxidant properties. However, its main active constituent, 4-nerolydilcatechol (4-NC), is sensitive to ultraviolet and visible light, which can limit the use of intermediate and final herbal preparations of this species. In the present work, coated multiparticulate solid dosage forms of P. umbellata were obtained with the purpose of increasing the stability of 4-NC. P. umbellata extract was used as a wetting liquid for the preparation of pellets by extrusion-spheronization. Pellets were coated in a fluidized bed by three different polymers (hydroxypropylmethylcellulose (HPMC), polyvynilpirrolidone K-30 (PVP-K30), and polyvinyl alcohol-polyethylene glycol graft-copolymer (PVAPEG)). 4-NC photostability was evaluated by an accelerated photostability protocol. Pellets showed a narrow size distribution and low friability. 4-NC photodegradation followed a second order degradation kinetics with similar k values for the percolate, uncoated pellets and HPMC coated pellets. Photoprotection was higher in pellets coated with PVP-K30 and PVA-PEG. PVA-PEG coated pellets with 6 and 9% weight gain resulted in a final concentration of 4-NC approximately cinco times higher than uncoated pellets or liquid extracts, suggesting the potential of this formulation as a multiparticulate solid dosage form for P. umbellata extracts.