IntroductionSuccessful stem cell therapy relies on large-scale generation of stem cells and their maintenance in a proliferative multipotent state. This study aimed to establish a three-dimension culture system for large-scale generation of hWJ-MSC and investigated the self-renewal activity, genomic stability and multi-lineage differentiation potential of such hWJ-MSC in enhancing skin wound healing.MethodshWJ-MSC were seeded on gelatin microbeads and cultured in spinning bottles (3D). Cell proliferation, karyotype analysis, surface marker expression, multipotent differentiation (adipogenic, chondrogenic, and osteogenic potentials), and expression of core transcription factors (OCT4, SOX2, NANOG, and C-MYC), as well as their efficacy in accelerating skin wound healing, were investigated and compared with those of hWJ-MSC derived from plate cultres (2D), using in vivo and in vitro experiments.ResultshWJ-MSC attached to and proliferated on gelatin microbeads in 3D cultures reaching a maximum of 1.1–1.30 × 107cells on 0.5 g of microbeads by days 8–14; in contrast, hWJ-MSC derived from 2D cultures reached a maximum of 6.5 -11.5 × 105 cells per well in a 24-well plate by days 6–10. hWJ-MSC derived by 3D culture incorporated significantly more EdU (P < 0.05) and had a significantly higher proliferation index (P < 0.05) than those derived from 2D culture. Immunofluorescence staining, real-time PCR, flow cytometry analysis, and multipotency assays showed that hWJ-MSC derived from 3D culture retained MSC surface markers and multipotency potential similar to 2D culture-derived cells. 3D culture-derived hWJ-MSC also retained the expression of core transcription factors at levels comparable to their 2D culture counterparts. Direct injection of hWJ-MSC derived from 3D or 2D cultures into animals exhibited similar efficacy in enhancing skin wound healing.ConclusionsThus, hWJ-MSC can be expanded markedly in gelatin microbeads, while retaining MSC surface marker expression, multipotent differential potential, and expression of core transcription factors. These cells also efficiently enhanced skin wound healing in vivo, in a manner comparable to that of hWJ-MSC obtained from 2D culture.

Platelet-derived growth factor (PDGF) is a potent moderator of soft tissue repair through induction of the inflammatory phase of repair and subsequent enhanced collagen deposition. We examined the effect of recombinant BB homodimer PDGF (rPDGF-BB) applied to rat craniotomy defects, treated with and without bovine osteogenin (OG), to see if bone regeneration would be stimulated. Implants containing 0, 20

Accurately classify teeth category is important in further dental diagnosis. Analyzing huge dental data, that is, identifying the teeth category, is often a hard task. Current automatic methods are based on computer vision and deep learning approaches. In this study, we aimed to classify the teeth category into four classes: incisor, canine, premolar, and molar. Cone beam computed tomography was used to collect the data. We proposed a seven‐layer deep convolutional neural network with global average pooling to identify teeth category. Data augmentation method was used to enlarge the size of training dataset. The results showed the sensitivities of incisor, canine, premolar, and molar teeth are 88%, 86%, 84%, and 90%, respectively. The average sensitivity is 87.0%. We validated max pooling gives better results than average pooling. Our method is better than three state‐of‐the‐art approaches.

The use of human mesenchymal stem cells (hMSCs) in cell therapies has increased the demand for strategies that allow efficient cell scale-up. Preliminary data on the three-dimensional (3D) spinner culture describing the potential use of microcarriers for hMSCs culture scale-up have been reported. We exploited a rich source of autologous stem cells (human hair follicle) and demonstrated the robust in vitro long-term expansion of human hair follicle-derived mesenchymal stem cells (hHF-MSCs) by using CultiSpher(®)-G microcarriers. We analyzed the feasibility of 3D culture by using hHF-MSCs/CultiSpher(®)-G microcarrier constructs for its potential applicability in regenerative medicine by comparatively analyzing the performance of hHF-MSCs adhered to the CultiSpher(®)-G microspheres in 3D spinner culture and those grown on the gelatin-coated plastic dishes (2D culture), using various assays. We showed that the hHF-MSCs seeded at various densities quickly adhered to and proliferated well on the microspheres, thus generating at least hundreds of millions of hHF-MSCs on 1 g of CultiSpher(®)-G within 12 days. This resulted in a cumulative cell expansion of greater than 26-fold. Notably, the maximum and average proliferation rates in 3D culture were significantly greater than that of the 2D culture. However, the hHF-MSCs from both the cultures retained surface marker and nestin expression, proliferation capacity and differentiation potentials toward adipocytes, osteoblasts and smooth muscle cells and showed no significant differences as evidenced by Edu incorporation, cell cycle, colony formation, apoptosis, biochemical quantification and qPCR assays.

The periodontal ligament (PDL) is a specific connective tissue composed of organized and aligned collagenous fibers that fix the tooth root in the alveolar bone. The alignment of PDL fibers and their function have been neglected in the past, as many studies investigated the regeneration of the periodontium, including alveolar bone and cementum regeneration. In this study, we fabricated biodegradable aligned fibers (ε-caprolactone/collagen) by near-field electrospinning (NFE) to control the arrangement of human periodontal ligament stem cells (hPDLSCs), aiming to guide the oriented regeneration of the periodontal ligament. Compared with random electrospun fibers, the in vitro study investigated the effects of nanotopography on stem cell differentiation of hPDLSCs. The hPDLSCs were identified by flow cytometry, and the multipotency of hPDLSCs was confirmed by successful osteogenic induction. The hPDLSCs were co-cultured with aligned and random fibers. The cell morphology was observed by confocal micrograph and scanning electron micrograph, which showed that aligned fibers could guide the orientation and elongation of hPDLSCs. The expression of periodontal ligament-related genes was higher when cultured with aligned fibers than when cultured with random fibers. In conclusion, via near-field electrospinning, aligned biodegradable fibers were prepared and guided the orientation arrangement of hPDLSCs, providing a better microenvironment for periodontal ligament regeneration. This technology might be further used in the regeneration of tissues in a given direction.