Co-Culture of Mesenchymal Stem Cells and Ligamentocytes on Triphasic Embroidered Poly(L-lactide-co-ε-caprolactone) and Polylactic Acid Scaffolds for Anterior Cruciate Ligament Enthesis Tissue Engineering.

Successful anterior cruciate ligament (ACL) reconstructions strive for a firm bone-ligament integration. With the aim to establish an enthesis-like construct, embroidered functionalized scaffolds were colonized with spheroids of osteogenically differentiated human mesenchymal stem cells (hMSCs) and lapine (l) ACL fibroblasts in this study. These triphasic poly(L-lactide-co-ε-caprolactone) and polylactic acid (P(LA-CL)/PLA) scaffolds with a bone-, a fibrocartilage transition- and a ligament zone were colonized with spheroids directly after assembly (DC) or with 14-day pre-cultured lACL fibroblast and 14-day osteogenically differentiated hMSCs spheroids (=longer pre-cultivation, LC).

Determination of the Entire Stent Surface Area by a New Analytical Method.

Stenting is a widely used treatment procedure for coronary artery disease around the world. Stents have a complex geometry, which makes the characterization of their corrosion difficult due to the absence of a mathematical model to calculate the entire stent surface area (ESSA). Therefore, corrosion experiments with stents are mostly based on qualitative analysis.

Increased pore size of scaffolds improves coating efficiency with sulfated hyaluronan and mineralization capacity of osteoblasts.

Background: Delayed bone regeneration of fractures in osteoporosis patients or of critical-size bone defects after tumor resection are a major medical and socio-economic challenge. Therefore, the development of more effective and osteoinductive biomaterials is crucial.

Methods: We examined the osteogenic potential of macroporous scaffolds with varying pore sizes after biofunctionalization with a collagen/high-sulfated hyaluronan (sHA3) coating in vitro The three-dimensional scaffolds were made up from a biodegradable three-armed lactic acid-based macromer (TriLA) by cross-polymerization.

Synergistic effect of bimodal pore distribution and artificial extracellular matrices in polymeric scaffolds on osteogenic differentiation of human mesenchymal stem cells.

The main objective of this study was to enhance the biological performance of resorbable polymeric scaffolds for bone tissue engineering. Specifically, we focused on both microstructure and surface modification of the scaffolds to augment adhesion, proliferation and osteogenic differentiation of human mesenchymal stem cells (hMSC). Moreover, a new cell seeding method assuring 90% seeding efficiency on the scaffolds was developed.

Influence of estrogen on individual exercise motivation and bone protection in ovariectomized rats.

Bone protection and metabolism are directly linked to estrogen levels, but exercise is also considered to have bone protective effects. Reduced estrogen levels lead to a variety of disorders, for example, bone loss and reduced movement drive. The objective of this study was to investigate the effects of estrogen on individual voluntary exercise motivation and bone protection.

A standardized Humulus lupulus (L.) ethanol extract partially prevents ovariectomy-induced bone loss in the rat without induction of adverse effects in the uterus.

Background: Hops (Humulus lupulus (L.)) dietary supplements are of interest as herbal remedies to alleviate menopausal symptoms, such as hot flushes, depression and anxiety. So far, the evidence regarding estrogenic and related properties of hops preparations has been considered insufficient for a market authorization for menopausal indications.

Collagen/glycosaminoglycan coatings enhance new bone formation in a critical size bone defect - A pilot study in rats.

Bone regeneration in critical size bone defects still represents an important but unsolved clinical problem. Glycosaminoglycans (GAGs) like chondroitin sulfate (CS) or hyaluronan (HA) are important multifunctional components of the extracellular matrix (ECM) in bone and may stimulate bone healing by recruitment of mesenchymal stromal cells and by supporting their differentiation. Sulfation of GAGs affects their biological activity and thus their interactions with growth factors and/or cells involved in the bone healing process.

Sulfated hyaluronan improves bone regeneration of diabetic rats by binding sclerostin and enhancing osteoblast function.

Bone fractures in patients with diabetes mellitus heal poorly and require innovative therapies to support bone regeneration. Here, we assessed whether sulfated hyaluronan included in collagen-based scaffold coatings can improve fracture healing in diabetic rats. Macroporous thermopolymerized lactide-based scaffolds were coated with collagen including non-sulfated or sulfated hyaluronan (HA/sHA3) and inserted into 3 mm femoral defects of non-diabetic and diabetic ZDF rats.

The effect of SDF-1α on low dose BMP-2 mediated bone regeneration by release from heparinized mineralized collagen type I matrix scaffolds in a murine critical size bone defect model.

The treatment of critical size bone defects represents a challenge. The growth factor bone morphogenetic protein 2 (BMP-2) is clinically established but has potentially adverse effects when used at high doses. The aim of this study was to evaluate if stromal derived factor-1 alpha (SDF-1α) and BMP-2 released from heparinized mineralized collagen type I matrix (MCM) scaffolds have a cumulative effect on bone regeneration.

Highly adjustable biomaterial networks from three-armed biodegradable macromers.

Unlabelled: Biocompatible material platforms with adjustable properties and option for chemical modification are warranted for site-specific biomedical applications. To this end, three-armed biodegradable macromers of well-defined chemical characteristics were prepared from trivalent alcohols with different degrees of ethoxylation and different lengths of oligoester domains. A platform of 15 different macromers was established.

Periosteal microcirculatory reactions in a zoledronate-induced osteonecrosis model of the jaw in rats.

Objectives: Nitrogen-containing bisphosphonates induce osteonecrosis mostly in the jaw and less frequently in other bones. Because of the crucial role of periosteal perfusion in bone repair, we investigated zoledronate-induced microcirculatory reactions in the mandibular periosteum in comparison with those in the tibia in a clinically relevant model of bisphosphonate-induced medication-related osteonecrosis of the jaw (MRONJ).

Materials And Methods: Sprague-Dawley rats were treated with zoledronate (ZOL; 80 i.

WNT5A has anti-prostate cancer effects in vitro and reduces tumor growth in the skeleton in vivo.

Prostate cancer is the most frequent malignancy in men, and a major cause of prostate cancer-related death is attributable to bone metastases. WNT5A is known to influence the clinical outcome of various cancer types, including prostate cancer, but the exact mechanisms remain unknown. The goal of this study was to assess the relevance of WNT5A for the development and progression of prostate cancer.

Increased bone remodelling around titanium implants coated with chondroitin sulfate in ovariectomized rats.

Coating titanium implants with artificial extracellular matrices based on collagen and chondroitin sulfate (CS) has been shown to enhance bone remodelling and de novo bone formation in vivo. The aim of this study was to evaluate the effect of estrogen deficiency and hormone replacement therapy (HRT) on the osseointegration of CS-modified Ti implants. 30 adult female, ovariectomized Wistar rats were fed either with an ethinyl-estradiol-rich diet (E) to simulate a clinical relevant HRT or with a genistein-rich diet (G) to test an alternative therapy based on nutritionally relevant phytoestrogens.

Effects of parathyroid hormone on bone mass, bone strength, and bone regeneration in male rats with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is associated with increased skeletal fragility and impaired fracture healing. Intermittent PTH therapy increases bone strength; however, its skeletal and metabolic effects in diabetes are unclear. We assessed whether PTH improves skeletal and metabolic function in rats with T2DM.

Impact of a functionalized olive oil extract on the uterus and the bone in a model of postmenopausal osteoporosis.

Purpose: The Mediterranean diet rich in fruits, vegetables and olive oil has been related to a lower osteoporosis incidence and accordingly to a reduced fracture risk. These observations might be mediated by the active constituents of extra virgin olive oil, and especially polyphenols. In the context of exploring the features of olive oil active constituents on postmenopausal osteoporosis, an extra virgin olive oil total polyphenolic fraction (TPF) was isolated and its effect on the bone loss attenuation was investigated.

Embroidered and surface coated polycaprolactone-co-lactide scaffolds: a potential graft for bone tissue engineering.

Tissue engineering and regenerative techniques targeting bone include a broad range of strategies and approaches to repair, augment, replace or regenerate bone tissue. Investigations that are aimed at optimization of these strategies until clinical translation require control of systemic factors as well as modification of a broad range of key parameters. This article reviews a possible strategy using a tissue engineering approach and systematically describes a series of experiments evaluating the properties of an embroidered and surface coated polycaprolactone-co-lactide scaffold being considered as bone graft substitute for large bone defects.

Surface modification of implants in long bone.

Coatings of orthopedic implants are investigated to improve the osteoinductive and osteoconductive properties of the implant surfaces and thus to enhance periimplant bone formation. By applying coatings that mimic the extracellular matrix a favorable environment for osteoblasts, osteoclasts and their progenitor cells is provided to promote early and strong fixation of implants. It is known that the early bone ongrowth increases primary implant fixation and reduces the risk of implant failure.

Healing properties of surface-coated polycaprolactone-co-lactide scaffolds: a pilot study in sheep.

The aim of this pilot study was to evaluate the bioactive, surface-coated polycaprolactone-co-lactide scaffolds as bone implants in a tibia critical size defect model. Polycaprolactone-co-lactide scaffolds were coated with collagen type I and chondroitin sulfate and 30 piled up polycaprolactone-co-lactide scaffolds were implanted into a 3 cm sheep tibia critical size defect for 3 or 12 months (n = 5 each). Bone healing was estimated by quantification of bone volume in the defects on computer tomography and microcomputer tomography scans, plain radiographs, biomechanical testing as well as by histological evaluations.

Sclerostin antibody treatment improves bone mass, bone strength, and bone defect regeneration in rats with type 2 diabetes mellitus.

Type 2 diabetes mellitus results in increased risk of fracture and delayed fracture healing. ZDF fa/fa rats are an established model of type 2 diabetes mellitus with low bone mass and delayed bone healing. We tested whether a sclerostin-neutralizing antibody (Scl-AbVI) would reverse the skeletal deficits of diabetic ZDF rats.

Comparison of estrogenic responses in bone and uterus depending on the parity status in Lewis rats.

The reproductive transition of women through peri- to postmenopause is characterized by changes in steroid hormone levels due to the cessation of the ovarian function. Beside several complaints associated with these hormonal changes, the deterioration of the trabecular bone micro-architecture and the loss of skeletal mass can cause osteoporosis. At this life stage, women often have a reproductive history of one to several pregnancies.

Establishment of a femoral critical-size bone defect model in immunodeficient mice.

Background: The development of innovative therapies for bone regeneration requires the use of advanced site-specific bone defect small-animal models. The achievement of proper fixation with a murine model is challenging due to the small dimensions of the murine femur. The aim of this investigation was to find the optimal defect size for a murine critical-size bone defect model using external fixation method.

Estimation of an early meaningful time point of bone parameter changes in application to an osteoporotic rat model with in vivo microcomputed tomography measurements.

The commonly used preclinical animal model of postmenopausal osteoporosis is the mature ovariectomized rat, whereby cessation of ovarian oestrogen production consequently results in bone volume reduction. The study aim was to precisely define the time course of structural changes resulting from ovariectomy and thereby reduce the time animals have to be treated to judge the effects of osteoporosis treatment. For this purpose, we assessed architectural changes by microcomputed tomography (μCT) during 10 weeks following ovariectomy or sham surgery at two-week intervals.

Regulation of bone mass and osteoclast function depend on the F-actin modulator SWAP-70.

Bone remodeling involves tightly regulated bone-resorbing osteoclasts and bone-forming osteoblasts. Determining osteoclast function is central to understanding bone diseases such as osteoporosis and osteopetrosis. Here, we report a novel function of the F-actin binding and regulatory protein SWAP-70 in osteoclast biology.

Comparison of bone-implant contact and bone-implant volume between 2D-histological sections and 3D-SRµCT slices.

Histological imaging is still considered the gold standard for analysing bone formation around metallic implants. Generally, a limited number of histological sections per sample are used for the approximation of mean values of peri-implant bone formation. In this study we compared statistically the results of bone-implant contact (BIC) and bone-implant volume (BIV) obtained by histological sections, with those obtained by X-ray absorption images from synchrotron radiation micro-computed tomography (SRµCT) using osseointegrated screw-shaped implants from a mini-pig study.