The poly (l-lactid-co-glycolide; PLGA) fiber component of brushite-forming calcium phosphate cement induces the osteogenic differentiation of human adipose tissue-derived stem cells

Abstract

A brushite-forming calcium phosphate cement (CPC) was mechanically stabilized by addition of poly (l-lactid-co-glycolide; PLGA) fibers (≤10% w/w). It proved highly biocompatible and its fiber component enhanced bone formation in a sheep lumbar vertebroplasty model. However, possible effects on the osteogenic differentiation of resident mesenchymal stem cells (MSCs) remained unexplored. The present study used a novel approach, simultaneously analyzing the influence of a solid CPC scaffold and its relatively low PLGA proportion (a mimicry of natural bone) on osteogenic, chondrogenic, and adipogenic differentiation, as well as the pluripotency of human adipose tissue-derived mesenchymal stem cells (hASCs). hASCs were cultured on CPC discs with/without PLGA fibers (5% and 10%) in the absence of osteogenic medium for 3, 7, and 14 d. Gene expression of osteogenic markers (Runx2, osterix, alkaline phosphatase, collagen I, osteonectin, osteopontin, osteocalcin), chondrogenic markers (collagen II, Sox9, aggrecan), adipogenic markers (PPARG, Leptin, and FABP4), and pluripotency markers (Nanog, Tert, Rex) was analyzed by RT-PCR. The ability of hASCs to synthesize alkaline phosphatase was also evaluated. Cell number and viability were determined by fluorescein diacetate/propidium iodide staining. Compared to pure CPC, cultivation of hASCs on fiber-reinforced CPC transiently induced the gene expression of Runx2 and osterix (day 3), and long-lastingly augmented the expression of alkaline phosphatase (and its enzyme activity), collagen I, and osteonectin (until day 14). In contrast, augmented expression of all chondrogenic, adipogenic, and pluripotency markers was limited to day 3, followed by significant downregulation. Cultivation of hASCs on fiber-reinforced CPC reduced the cell number, but not the proportion of viable cells (viability > 95%). The PLGA component of fiber-reinforced, brushite-forming CPC supports long-lasting osteogenic differentiation of hASCs, whereas chondrogenesis, adipogenesis, and pluripotency are initially augmented, but subsequently suppressed. In view of parallel animal results, PLGA fibers may represent an interesting clinical target for future improvement of CPC- based bone regeneration.

MicroRNA-27b targets CBFB to inhibit differentiation of human bone marrow mesenchymal stem cells into hypertrophic chondrocytes

“…MicroRNAs have emerged as potent therapeutic targets in the treatment of multiple diseases and injuries. To effectively improve intercellular miRNA levels and enhance their therapeutic efficacy, multiple exogenous microRNA delivery systems have been developed, including lentiviral and adenoviral vectors [ 71 ], poly (lactide-co-glycolide) [ 72 ], and liposomes [ 73 ]. In this study, we selected lentiviruses as our vector for delivering exogenous miR-27b.…”

In Vitro Release of Bioactive Bone Morphogenetic Proteins (GDF5, BB-1, and BMP-2) from a PLGA Fiber-Reinforced, Brushite-Forming Calcium Phosphate Cement

“…hASCs were isolated using a well-established method described previously ([8] and references therein). For cell isolation, subcutaneous adipose tissue was collected from both male and female subjects ( n = 8, mean age 39.8 ± 4.9 years).…”

“…Examples for the mineral components include calcium phosphate cement (CPC; [1,2]), bioceramics [3], biosilicates [4], graphene oxides [5], and clay nanotubes [6], whereas examples of organic component are poly( l -lactide- co -glycolide) acid (PLGA; [3,4,5]), carboxylmethylcellulose, and hyaluronan-bisphosphonate [2] or chitosan–gelatine–agarose hydrogels [1,6]. On the basis of promising previous in vitro and in vivo studies with a biodegradable, brushite-forming CPC with reinforcing PLGA fibers [7,8,9,10,11,12], the present study is focused on this particular mineral–organic bone replacement composite.…”

“…In terms of CPC modifications, recent own studies have demonstrated that the inclusion of poly ( l -lactide- co -glycolide) acid (PLGA) fibers in a brushite-forming CPC on one hand considerably improves its mechanical strength and fracture toughness ([26,27]; including scanning electron microscopy of the CPC), and on the other hand enhances in vitro osteogenic differentiation [7,8] and in vivo bone formation [9].…”

Osteogenic Differentiation of Human Adipose Tissue-Derived MSCs by Non-Toxic Calcium Poly(ethylene phosphate)s

“…One of the most promising approaches involves the use of mesenchymal stem cells (MSCs) that are seeded into 3D scaffolds and induce bone generation by osteoinductive cues [1,[4][5][6][7]. The design of such 3D scaffolds as a bone void filler can be implemented at the interface of organic chemistry, polymer chemistry, material science and cell biology by the development of the composites containing biodegradable synthetic polymers and calcium phosphates [8][9][10][11]. This approach seems to be prospective due to the variability of polymer characteristics [12][13][14][15] and osteoinductivity of calcium and phosphate ions [16,17].…”