Monocyte-derived extracellular vesicles stimulate cytokine secretion and gene expression of matrix metalloproteinases by mesenchymal stem/stromal cells.

Unlabelled: Intercellular communication is essential in bone remodelling to ensure that new bone is formed with only temporary bone loss. Monocytes (MCs) and osteoclasts actively take part in controlling bone remodelling by providing signals that promote osteogenic differentiation of mesenchymal stem/stromal cells (MSCs). Extracellular vesicles (EVs) have attracted attention as regulators of bone remodelling.

Comparison of Poly(l-lactide-co-ɛ-caprolactone) and Poly(trimethylene carbonate) Membranes for Urethral Regeneration: An In Vitro and In Vivo Study.

Urethral defects are normally reconstructed using a patient's own genital tissue; however, in severe cases, additional grafts are needed. We studied the suitability of poly(l-lactide-co-ɛ-caprolactone) (PLCL) and poly(trimethylene carbonate) (PTMC) membranes for urethral reconstruction in vivo. Further, the compatibility of the materials was evaluated in vitro with human urothelial cells (hUCs).

Surface Curvature Differentially Regulates Stem Cell Migration and Differentiation via Altered Attachment Morphology and Nuclear Deformation.

Signals from the microenvironment around a cell are known to influence cell behavior. Material properties, such as biochemical composition and substrate stiffness, are today accepted as significant regulators of stem cell fate. The knowledge of how cell behavior is influenced by 3D geometric cues is, however, strongly limited despite its potential relevance for the understanding of tissue regenerative processes and the design of biomaterials.

Poly(trimethylene carbonate) as an elastic biodegradable film for human embryonic stem cell-derived retinal pigment epithelial cells.

Human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cell therapies show tremendous potential for the treatment of retinal degenerative diseases. A tissue engineering approach, where cells are delivered to the subretinal space on a biodegradable carrier as a sheet, shows great promise for these RPE cell therapies. The aim of the present study was to assess whether a flexible, elastic and biodegradable poly(trimethylene carbonate) (PTMC) film promotes the formation of functional hESC-RPE and performs better than often used biodegradable poly(d,l-lactide) (PDLLA) film.

Electrically Stimulated Adipose Stem Cells on Polypyrrole-Coated Scaffolds for Smooth Muscle Tissue Engineering.

We investigated the use of polypyrrole (PPy)-coated polymer scaffolds and electrical stimulation (ES) to differentiate adipose stem cells (ASCs) towards smooth muscle cells (SMCs). Since tissue engineering lacks robust and reusable 3D ES devices we developed a device that can deliver ES in a reliable, repeatable, and cost-efficient way in a 3D environment. Long pulse (1 ms) or short pulse (0.

UV Cross-Linkable Graphene/Poly(trimethylene Carbonate) Composites for 3D Printing of Electrically Conductive Scaffolds.

Conductive, flexible graphene/poly(trimethylene carbonate) (PTMC) composites were prepared. Addition of just 3 wt % graphene to PTMC oligomers functionalized with methacrylate end-groups followed by UV cross-linking resulted in more than 100% improvement in tensile strength and enhanced electrical conductivity by orders of magnitude without altering the processability of the host material. The addition of graphene also enhanced mesenchymal stem cell (MSC) attachment and proliferation.

Differentiation of adipose stem cells seeded towards annulus fibrosus cells on a designed poly(trimethylene carbonate) scaffold prepared by stereolithography.

Cell-based therapies could potentially restore the biomechanical function and enhance the self-repair capacity of annulus fibrosus (AF) tissue. However, choosing a suitable cell source and scaffold design are still key challenges. In this study, we assessed the in vitro ability of human adipose stem cells (hASCs), an easily available cell source to produce AF-like matrix in novel AF-mimetic designed scaffolds based on poly(trimethylene carbonate) and built by stereolithography.

Human Adipose Stem Cells Differentiated on Braided Polylactide Scaffolds Is a Potential Approach for Tendon Tissue Engineering.

Growing number of musculoskeletal defects increases the demand for engineered tendon. Our aim was to find an efficient strategy to produce tendon-like matrix in vitro. To allow efficient differentiation of human adipose stem cells (hASCs) toward tendon tissue, we tested different medium compositions, biomaterials, and scaffold structures in preliminary tests.

Bone healing in rabbit calvarial critical-sized defects filled with stem cells and growth factors combined with granular or solid scaffolds.

Purpose: In pediatric neurosurgery, decompressive craniectomy and correction of congenital cranial anomalies can result in major cranial defects. Corrective cranioplasty for the repair of these critical-sized defects is not only a cosmetic issue. The limited availability of suitable autogenous bone and the morbidity of donor site harvesting have driven the search for new approaches with biodegradable and bioactive materials.

Polypyrrole coating on poly-(lactide/glycolide)-β-tricalcium phosphate screws enhances new bone formation in rabbits.

Polypyrrole (PPy) has gained interest as an implant material due to its multifunctional properties and its high compatibility with several cell and tissue types. For the first time, the biocompatibility and osteointegration of PPy coating, incorporated with chondroitin sulfate (CS), were studied in vivo by implanting PPy-coated bioabsorbable bone fixation composite screws of poly-(lactide/glycolide) copolymer (PLGA) and β-tricalcium phosphate (TCP) into New Zealand white rabbits. Uncoated bioabsorbable polymer composite screws and commercially available stainless steel cortical screws were used as reference implants.

μCT based assessment of mechanical deformation of designed PTMC scaffolds.

Background: Advances in rapid-prototyping and 3D printing technologies have enhanced the possibilities in preparing designed architectures for tissue engineering applications. A major advantage in custom designing is the ability to create structures with desired mechanical properties. While the behaviour of a designed scaffold can be simulated using bulk material properties, it is important to verify the behaviour of a printed scaffold at the microstructure level.

Autologous adipose stem cells in treatment of female stress urinary incontinence: results of a pilot study.

The purpose of our study was to find out whether transurethral injections of autologous adipose stem cells (ASCs) are an effective and a safe treatment for female stress urinary incontinence (SUI). We treated five SUI patients with ASCs combined with bovine collagen gel and saline. Prior to the treatment, the ASCs were isolated from subcutaneous fat and expanded for 3 weeks in a good manufacturing practice-level laboratory.

Comparison of chondroitin sulfate and hyaluronic Acid doped conductive polypyrrole films for adipose stem cells.

Polypyrrole (PPy) is a conductive polymer that has aroused interest due to its biocompatibility with several cell types and high tailorability as an electroconductive scaffold coating. This study compares the effect of hyaluronic acid (HA) and chondroitin sulfate (CS) doped PPy films on human adipose stem cells (hASCs) under electrical stimulation. The PPy films were synthetized electrochemically.

Exogenously added BMP-6, BMP-7 and VEGF may not enhance the osteogenic differentiation of human adipose stem cells.

In the present study bone morphogenetic protein (BMP)-6 alone or in synergy with BMP-7 and vascular endothelial growth factor (VEGF) were tested with human adipose stem cells (hASCs) seeded on cell culture plastic or 3D bioactive glass. Osteogenic medium (OM) was used as a positive control for osteogenic differentiation. The same growth factor groups were also tested combined with OM.

Surface properties and interaction forces of biopolymer-doped conductive polypyrrole surfaces by atomic force microscopy.

Surface properties and electrical charges are critical factors elucidating cell interactions on biomaterial surfaces. The surface potential distribution and the nanoscopic and microscopic surface elasticity of organic polypyrrole-hyaluronic acid (PPy-HA) were studied by atomic force microscopy (AFM) in a fluid environment in order to explain the observed enhancement in the attachment of human adipose stem cells on positively charged PPy-HA films. The electrostatic force between the AFM tip and a charged PPy-HA surface, the tip-sample adhesion force, and elastic moduli were estimated from the AFM force curves, and the data were fitted to electrostatic double-layer and elastic contact models.

Effects of different serum conditions on osteogenic differentiation of human adipose stem cells in vitro.

Introduction: Currently, human adipose stem cells (hASCs) are differentiated towards osteogenic lineages using culture medium supplemented with L-ascorbic acid 2-phosphate (AsA2-P), dexamethasone (Dex) and beta-glycerophosphate (β-GP). Because this osteogenic medium (OM1) was initially generated for the differentiation of bone marrow-derived mesenchymal stem cells, the component concentrations may not be optimal for the differentiation of hASCs. After preliminary screening, two efficient osteogenic media (OM2 and OM3) were chosen to be compared with the commonly used osteogenic medium (OM1).

Osteogenic medium is superior to growth factors in differentiation of human adipose stem cells towards bone-forming cells in 3D culture.

Human adipose stem cells (hASCs) have been recently used to treat bone defects in clinical practice. Yet there is a need for more optimal scaffolds and cost-effective approaches to induce osteogenic differentiation of hASCs. Therefore, we compared the efficiency of bone morphogenetic proteins (BMP-2 and BMP-7), vascular endothelial growth factor (VEGF), and osteogenic medium (OM) for the osteo-induction of hASCs in 3D culture.

Hollow fibers of poly(lactide-co-glycolide) and poly(ε-caprolactone) blends for vascular tissue engineering applications.

At present the manufacture of small-diameter blood vessels is one of the main challenges in the field of vascular tissue engineering. Currently available vascular grafts rapidly fail due to development of intimal hyperplasia and thrombus formation. Poly(lactic-co-glycolic acid) (PLGA) hollow fiber (HF) membranes have previously been proposed for this application, but as we show in the present work, they have an inhibiting effect on cell proliferation and rather poor mechanical properties.

Novel polypyrrole-coated polylactide scaffolds enhance adipose stem cell proliferation and early osteogenic differentiation.

An electrically conductive polypyrrole (PPy) doped with a bioactive agent is an emerging functional biomaterial for tissue engineering. We therefore used chondroitin sulfate (CS)-doped PPy coating to modify initially electrically insulating polylactide resulting in novel osteogenic scaffolds. In situ chemical oxidative polymerization was used to obtain electrically conductive PPy coating on poly-96L/4D-lactide (PLA) nonwoven scaffolds.

Effects of chitosan and bioactive glass modifications of knitted and rolled polylactide-based 96/4 L/D scaffolds on chondrogenic differentiation of adipose stem cells.

The performance of biodegradable knitted and rolled 3-dimensional (3D) polylactide-based 96/4 scaffolds modified with bioactive glass (BaG) 13-93, chitosan and both was compared with regard to the viability, proliferation and chondrogenic differentiation of rabbit adipose stem cells (ASCs). Scaffold porosities were determined by micro-computed tomography (μCT). Water absorption and degradation of scaffolds were studied during 28-day hydrolysis in Tris-buffer.

Characterizing and optimizing poly-L-lactide-co-ε-caprolactone membranes for urothelial tissue engineering.

Different synthetic biomaterials such as polylactide (PLA), polycaprolactone and poly-l-lactide-co-ε-caprolactone (PLCL) have been studied for urothelial tissue engineering, with favourable results. The aim of this research was to further optimize the growth surface for human urothelial cells (hUCs) by comparing different PLCL-based membranes: smooth (s) and textured (t) PLCL and knitted PLA mesh with compression-moulded PLCL (cPLCL). The effects of topographical texturing on urothelial cell response and mechanical properties under hydrolysis were studied.

Peri-Implant Tissue Findings in Bone Grafted Oral Cancer Patients Compared to non Bone Grafted Patients without Oral Cancer.

Objectives: The aim of this study was to compare microbiological, histological, and mechanical findings from tissues around osseointergrated dental implants in patients who had undergone tumour resection and subsequent bone grafting with non bone grafted patients without a history of oral cancer and to develop an effective tool for the monitoring of the peri-implant tissues. A third aim was to assess and compare the masticatory function of the two patient groups after reconstruction with dental implants.

Material And Methods: A total of 20 patients were divided into 2 groups.

In Vivo and In Vitro Study of a Polylactide-Fiber-Reinforced β-Tricalcium Phosphate Composite Cage in an Ovine Anterior Cervical Intercorporal Fusion Model.

A poly-70L/30DL-lactide (PLA70)-β-tricalcium phosphate (β-TCP) composite implant reinforced by continuous PLA-96L/4D-lactide (PLA96) fibers was designed for in vivo spinal fusion. The pilot study was performed with four sheep, using titanium cage implants as controls. The composite implants failed to direct bone growth as desired, whereas the bone contact and the proper integration were evident with controls 6 months after implantation.

The effects of vibration loading on adipose stem cell number, viability and differentiation towards bone-forming cells.

Mechanical stimulation is an essential factor affecting the metabolism of bone cells and their precursors. We hypothesized that vibration loading would stimulate differentiation of human adipose stem cells (hASCs) towards bone-forming cells and simultaneously inhibit differentiation towards fat tissue. We developed a vibration-loading device that produces 3g peak acceleration at frequencies of 50 and 100 Hz to cells cultured on well plates.

Comparison of a poly-L-lactide-co-ε-caprolactone and human amniotic membrane for urothelium tissue engineering applications.

The reconstructive surgery of urothelial defects, such as severe hypospadias is susceptible to complications. The major problem is the lack of suitable grafting materials. Therefore, finding alternative treatments such as reconstruction of urethra using tissue engineering is essential.