Alkaline Phosphatase Specific Activity Research Articles

Osteoblast-Derived Matrix Vesicles Exhibit Exosomal Traits and a Unique Subset of microRNA: Their Caveolae-Dependent Endocytosis Results in Reduced Osteogenic Differentiation.

Matrix vesicles (MVs) are nano-sized extracellular vesicles that are anchored in the extracellular matrix (ECM). In addition to playing a role in biomineralization, osteoblast-derived MVs were recently suggested to have regulatory duties. The aims of this study were to establish the characteristics of osteoblast-derived MVs in the context of extracellular vesicles like exosomes, assess their role in modulating osteoblast differentiation, and examine their mechanism of uptake. MVs were isolated from the ECM of MG63 human osteoblast-like cell cultures and characterized via enzyme activity, transmission electron microscopy, nanoparticle tracking analysis, Western blot, and small RNA sequencing. Osteoblasts were treated with MVs from two different culture conditions (growth media [GM]; osteogenic media [OM]) to evaluate their effects on the differentiation and production of inflammatory markers and on macrophage polarization. MV endocytosis was assessed using a lipophilic, fluorescent dye and confocal microscopy with the role of caveolae determined using methyl-β-cyclodextrin. MVs exhibited a four-fold enrichment in alkaline phosphatase specific activity compared to plasma membranes; were 50-150 nm in diameter; possessed exosomal markers CD63, CD81, and CD9 and endosomal markers ALIX, TSG101, and HSP70; and were selectively enriched in microRNA linked to an anti-osteogenic effect and to M2 macrophage polarization. Treatment with GM or OM MVs decreased osteoblast differentiation. Osteoblasts endocytosed MVs using a mechanism that involves caveolae. These results support the hypothesis that osteoblasts produce MVs that participate in the regulation of osteogenesis.

Response of Soil Absolute and Specific Enzyme Activities to Long-Term Application of Organic Fertilizer to Solonetz in Northeast China

Soil organic carbon (SOC) and microbial biomass carbon (MBC) are highly correlated with enzyme activities. Specific enzyme activities can exclude the autocorrelation between enzyme activity and SOC and MBC. However, the responses of absolute and specific enzyme activities to saline–alkali properties remains unclear. In this study, the absolute and specific enzyme activities of cellobiose hydrolase, β-glucosidase, arylsulfatase, alkaline phosphatase, and urease were measured in soils with 10, 15, 18, 21, and 26 years of organic fertilizer application in contrast to soils without organic fertilizer application. The results showed that long-term organic fertilizer application led to significantly increased in the absolute and specific enzyme activity and decrease in pH, electrical conductivity (EC), exchangeable sodium percentage (ESP), as well as sodium adsorption ratio (SAR5:1). In the structural equation model (SEM), the EC extremely limited the geometric mean of specific enzyme activity per unit of MBC (MBC-GMSEA) (path coefficient, −0.84, p < 0.001). Pearson’s correlation analysis showed that the correlations between EA/MBC and pH, EC, ESP, and SAR5:1 were higher than between the absolute soil enzyme activity and pH, EC, ESP, and SAR5:1. Of the parameters tested, EA/MBC was a more sensitive index to reflect the improvement effect of organic fertilizer on soils and evaluate the saline–alkali barrier.

Mammalian aminopeptidase A: biochemical characteristics, physiological roles and physiopathological implications

Abstract Aminopeptidases selectively hydrolyze an aminoacid residue from the amino terminus of proteins and peptides resulting in their activation or inactivation. These enzymes are mainly metallo and belong, among other, to the M1 family of peptidases. One of its members, membrane glutamyl aminopeptidase (APA, EC 3.4.11.7) participates in many physiological processes, such as peptide metabolism related with blood pressure control, and last step of protein degradation. Furthermore, the up regulation of APA has been implicated in the pathogenesis of various human disorders like cancers, hypertension and glomerulosclerosis. APA is thus a target for the development of inhibitors with potential biomedical applications. We review the most important structural and functional characteristics of mammalian APA, focusing on the most recent data. Additionally, we integrate the roles of APA in physio- and pathophysio-logical processes of biomedical relevance with the development of specific APA inhibitors.

The effect of epigenetic reprogramming using MI192 HDAC inhibitor on enhancing the osteogenesis of human adipose-derived stem cells in vitro.

The ability to control stem cell function is the key to stem cell-based therapy and living tissue regeneration. In natural conditions, histone deacetylases (HDAC) are regarded as the important defining epigenetic reprogramming for stem cell differentiation. To date, human adipose-derived stem cells (hADSCs) have been widely utilised for bone tissue engineering applications. The present study aimed to examine the effect of a novel HDAC2&3-selective inhibitor, MI192, on hADSCs epigenetic reprogramming for regulating its osteogenic potential in vitro. The results confirmed that MI192 treatment reduced the hADSCs viability in a time and dose-dependent manner. The optimal concentration and pre-treatment time of MI192 for hADSCs osteogenic induction was 30 μM and 2 days representatively. A quantitative biochemical assay confirmed that the pre-treatment with MI192 (30 μM) for 2 days significantly enhanced hADSCs alkaline phosphatase (ALP) specific activity (P<0.05) compared with that of the valproic acid (VPA) pre-treatment group. Real-time PCR analysis revealed that MI192 pre-treatment up-regulated hADSCs gene expressions of osteogenic markers (e.g., Runx2, Col1, and OCN) under the osteogenic induction. DNA flow cytometric analysis indicated that two days' pre-treatment with MI192 (30 μM) resulted in G2/M arrest in hADSCs and this G2/M arrest was reversible. Our results suggest that MI192 is capable of epigenetic reprogramming of hADSCs via HDAC inhibition for controlling the cell cycle, resulting in enhancing hADSCs osteogenic differentiation, which indicates the potential of using MI192 for promoting bone tissue regeneration.

Ethnic Minorities’ Experiences of Cardiac Rehabilitation: A Scoping Review

Cardiac rehabilitation (CR) can improve cardiovascular risk factors, decrease cardiac mortality, and promote healthy lifestyle behaviours. However, services remain underutilized by groups of ethnic minorities. The purpose of the study was to identify patients' personal CR experiences to identify the differences CR makes towards minorities' lifestyle. An initial electronic search was performed in 2021 for papers ranging from 2008-2020 across specific databases, including PubMed, EMBASE, APA PsycINFO, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Medline. Google Scholar was also used to supplement the search process and to identify studies performed within grey literature. A total of 1230 records were screened, of which 40 were assessed for eligibility. The final sample consisted of seven qualitative design studies that were identified for inclusion in this review. Based on patient personal experiences, this review identified that ethnic minorities continue to remain disadvantaged when accessing healthcare interventions, primarily as a result of cultural behaviours, linguistic barriers, socioeconomic status, religious and fatalistic beliefs, and low physician referral rates. More research is needed to elucidate this phenomenon and address these factors faced by ethnic minorities.

Specific alkaline phosphatase activity as an indicator of phosphorus status in the plankton community of a highly stratified oligotrophic Ombla Estuary

Specific alkaline phosphatase activity as an indicator of phosphorus status in the plankton community of a highly stratified oligotrophic Ombla Estuary

A comparative analysis of 3D printed scaffolds consisting of poly(lactic-co-glycolic) acid and different bioactive mineral fillers: aspects of degradation and cytocompatibility.

Their excellent mechanical properties, degradability and suitability for processing by 3D printing technologies make the thermoplastic polylactic acid and its derivatives favourable candidates for biomaterial-based bone regeneration therapies. In this study, we investigated whether bioactive mineral fillers, which are known to promote bone healing based on their dissolution products, can be integrated into a poly(L-lactic-co-glycolic) acid (PLLA-PGA) matrix and how key characteristics of degradation and cytocompatibility are influenced. The polymer powder was mixed with particles of CaCO3, SrCO3, strontium-modified hydroxyapatite (SrHAp) or tricalcium phosphates (α-TCP, β-TCP) in a mass ratio of 90 : 10; the resulting composite materials have been successfully processed into scaffolds by the additive manufacturing method Arburg Plastic Freeforming (APF). Degradation of the composite scaffolds was investigated in terms of dimensional change, bioactivity, ion (calcium, phosphate, strontium) release/uptake and pH development during long-term (70 days) incubation. The mineral fillers influenced the degradation behavior of the scaffolds to varying degrees, with the calcium phosphate phases showing a clear buffer effect and an acceptable dimensional increase. The amount of 10 wt% SrCO3 or SrHAp particles did not appear to be appropriate to release a sufficient amount of strontium ions to exert a biological effect in vitro. Cell culture experiments with the human osteosarcoma cell line SAOS-2 and human dental pulp stem cells (hDPSC) indicated the high cytocompatibility of the composites: For all material groups cell spreading and complete colonization of the scaffolds over the culture period of 14 days as well as an increase of the specific alkaline phosphatase activity, typical for osteogenic differentiation, were observed.

Dietary choline promotes growth, antioxidant capacity and immune response by modulating p38MAPK/p53 signaling pathways of juvenile Pacific white shrimp (Litopenaeus vannamei)

The objective of the present study was to evaluate the effects of dietary choline levels on growth performance, antioxidant capacity, innate immunity and hemocyte apoptosis of Litopenaeus vannamei. Six isonitrogenous and isolipidic diets were formulated to contain different choline levels: 2.91 (basal diet), 3.85, 4.67, 6.55, 10.70 and 18.90 g kg−1choline, respectively. The results indicated that shrimp fed diet with 4.67 g kg−1 choline had the highest final body weight (FBW), percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE), and activities of alkaline phosphatase (AKP) and phenoloxidase (PO) in hemolymph among all treatments. Shrimp fed diet with 18.90 g kg−1 choline exhibited significantly lower crude lipid in hepatopancreas than those fed diets with 2.91, 3.85, 4.67 and 6.55 g kg−1 choline (P < 0.05). The concentration of reactive oxygen species (ROS) and apoptosis rate in hemocytes significantly decreased with the increase of dietary choline levels (P < 0.05). Shrimp fed diets with 6.55, 10.70 and 18.90 g kg−1 choline had significantly higher scavenging ability of hydroxyl radical (SAHR) and total antioxidant capacity (T-AOC) in hemolymph than those fed diet with 2.91 g kg−1 choline (P < 0.05). Dietary choline supplementation down-regulated the expression of genes related to apoptosis such as caspase-1, caspase-3, caspase-8, p53, and p38MAPK in hemocytes (P < 0.05), while up-regulated the expression of anti-apoptosis gene bcl2 in hemocytes (P < 0.05). Overall, the results of the present study demonstrated that appropriate dietary choline could improve growth performance and feed utilization, enhance antioxidant capacity and innate immunity, and mitigate apoptosis in Litopenaeus vannamei. Moreover, the inhibition of hemocyte apoptosis by dietary choline may be regulated by the p38MAPK-p53 signaling pathway.

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Docosahexaenoic acid improves altered mineralization proteins, the decreased quality of hydroxyapatite crystals and suppresses oxidative stress induced by high glucose.

Patients with type 2 diabetes mellitus (DM2) experience an increased risk of fractures and a variety of bone pathologies, such as osteoporosis. The suggested mechanisms of increased fracture risk in DM2 include chronic hyperglycaemia, which provokes oxidative stress, alters bone matrix, and decreases the quality of hydroxyapatite crystals. Docosahexaenoic acid (DHA), an omega-3 fatty acid, can increase bone formation, reduce bone loss, and it possesses antioxidant/anti-inflammatory properties. The present study aimed to determine the effect of DHA on altered osteoblast mineralisation and increased reactive oxygen species (ROS) induced by high glucose concentrations. A human osteoblast cell line was treated with 5.5 mM glucose (NG) or 24 mM glucose (HG), alone or in combination with 10 or 20 µM DHA. The collagen type 1 (Col1) scaffold, the expression of osteocalcin (OCN) and bone sialoprotein type-II (BSP-II), the alkaline phosphatase (ALP) specific activity, the mineral quality, the production of ROS and the mRNA expression of nuclear factor erythroid 2-related factor-2 (NRF2) were analysed. Osteoblasts cultured in HG and treated with either DHA concentration displayed an improved distribution of the Col1 scaffold, increased OCN and BSP-II expression, increased NRF2 mRNA, decreased ALP activity, carbonate substitution and reduced ROS production compared with osteoblasts cultured in HG alone. DHA counteracts the adverse effects of HG on bone mineral matrix quality and reduces oxidative stress, possibly by increasing the expression of NRF2.

Effects of Ruzu, a Polyherbal Mixture, on Neurobehaviour and Expression of Serotonin and Dopamine Transporters in Rats.

There is increased possibility that combined herbal constituents may interact to increase toxicity and lower efficacy. Ruzu herbal bitters (RHB) is a blend of extracts from Curculigo pilosa, Uvaria chamae, and Citrullus colocynthis, each of which has been shown to possess important bio-effects. There is anecdotal evidence for efficacy of RHB in neurological disorders; however, there are no data on possible neurotoxic effects of RHB. Using behavioural, biochemical and molecular indices as surrogates of neurotoxicity, this study therefore evaluated the nervous system effects of RHB. Twenty male Wistar rats were divided into two groups - a control group and RHB group (n=10). RHB (0.5ml/kg) was administered to the RHB group twice daily while control group took water (0.5ml/kg). Treatments lasted 6 weeks after which behavioural tests were carried out. Animals were subsequently sacrificed and the expression of serotonin transporter (SERT) and dopamine transporter (DAT) was determined in the striatum by immunofluorescence while specific activities of catalase, alkaline phosphatase and gamma glutamyltransferase were determined. In the elevated plus maze and light and dark box tests which are models of anxiety, animals treated with RHB showed significant anxiety compared to control. They also showed impaired locomotor activity in the open field and wire hang tests. The activity of catalase was significantly increased in the brain of the RHB treated rats while an increase in the expression of both DAT and SERT was observed in the striatum.

Effects of Ruzu, a Polyherbal Mixture, on Neurobehaviour and Expression of Serotonin and Dopamine Transporters in Rats

There is increased possibility that combined herbal constituents may interact to increase toxicity and lower efficacy. Ruzu herbal bitters (RHB) is a blend of extracts from Curculigo pilosa, Uvaria chamae, and Citrullus colocynthis, each of which has been shown to possess important bio-effects. There is anecdotal evidence for efficacy of RHB in neurological disorders; however, there are no data on possible neurotoxic effects of RHB. Using behavioural, biochemical and molecular indices as surrogates of neurotoxicity, this study therefore evaluated the nervous system effects of RHB. Twenty male Wistar rats were divided into two groups – a control group and RHB group (n=10). RHB (0.5ml/kg) was administered to the RHB group twice daily while control group took water (0.5ml/kg). Treatments lasted 6 weeks after which behavioural tests were carried out. Animals were subsequently sacrificed and the expression of serotonin transporter (SERT) and dopamine transporter (DAT) was determined in the striatum by immunofluorescence while specific activities of catalase, alkaline phosphatase and gamma glutamyltransferase were determined. In the elevated plus maze and light and dark box tests which are models of anxiety, animals treated with RHB showed significant anxiety compared to control. They also showed impaired locomotor activity in the open field and wire hang tests. The activity of catalase was significantly increased in the brain of the RHB treated rats while an increase in the expression of both DAT and SERT was observed in the striatum

MI192 induced epigenetic reprogramming enhances the therapeutic efficacy of human bone marrows stromal cells for bone regeneration

Human bone marrow stromal cells (hBMSCs) have been extensively utilised for bone tissue engineering applications. However, they are associated with limitations that hinder their clinical utility for bone regeneration. Cell fate can be modulated via altering their epigenetic functionality. Inhibiting histone deacetylase (HDAC) enzymes have been reported to promote osteogenic differentiation, with HDAC3 activity shown to be causatively associated with osteogenesis. Therefore, this study aimed to investigate the potential of using an HDAC2 & 3 selective inhibitor - MI192 to induce epigenetic reprogramming of hBMSCs and enhance its therapeutic efficacy for bone formation. Treatment with MI192 caused a time-dose dependant reduction in hBMSCs viability. MI192 was also found to substantially alter hBMSCs epigenetic function through reduced HDAC activity and increased histone acetylation. hBMSCs were pre-treated with MI192 (50μM) for 48h prior to osteogenic induction. MI192 pre-treatment significantly upregulated osteoblast-related gene/protein expression (Runx2, ALP, Col1a and OCN) and enhanced alkaline phosphatase specific activity (ALPSA) (1.43-fold) (P≤0.001). Moreover, MI192 substantially increased hBMSCs extracellular matrix calcium deposition (1.4-fold) (P≤0.001) and mineralisation when compared to the untreated control. In 3D microtissue culture, MI192 significantly promoted hBMSCs osteoblast-related gene expression and ALPSA (> 2.41-fold) (P≤0.001). Importantly, MI192 substantially enhanced extracellular matrix deposition (ALP, Col1a, OCN) and mineralisation (1.67-fold) (P≤0.001) within the bioassembled-microtissue (BMT) construct. Following 8-week intraperitoneal implantation within nude mice, MI192 treated hBMSCs exhibited enhanced extracellular matrix deposition and mineralisation (2.39-fold) (P≤0.001) within the BMT when compared to the untreated BMT construct. Taken together, these results demonstrate that MI192 effectively altered hBMSCs epigenetic functionality and is capable of promoting hBMSCs osteogenic differentiation in vitro and in vivo, indicating the potential of using epigenetic reprogramming to enhance the therapeutic efficacy of hBMSCs for bone augmentation strategies.

Variations in digestive enzyme activity during larval development of cultured Pacific red snapperLutjanus peru

In the present study, the digestive enzyme activity during larval development in L. peru reared under intensive culture conditions was evaluated. The results revealed that L. peru larvae have the necessary enzymes to digest proteins, lipids and carbohydrates when nutritional reserves have been depleted at the onset of the exogenous feeding at 3 days after hatching (DAH) or 78 degree-days (DD). The activities of the digestive enzymes follow patterns similar to those previously reported in other related species. As in other marine fish larvae, the amylase specific activity decreased during larval development of L. peru. At 25 DAH (650 DD), the specific activities of lipase, alkaline phosphatase and acid phosphatase declined, while the specific activities of pepsin, trypsin and chymotrypsin increased. In contrast, the individual activity of all enzymes steadily increased with development. The time required to reach the maximum activity varies, suggesting a relative importance of different digestive enzymes during the different developmental stages of the digestive tract. In our study, the highest activity was reached by amylase at Stage I and early Stage II (3–11 DAH or 78–286 DD), by lipase and both acid and alkaline phosphatases at the end of Stage II (18–22 DAH or 468–572 DD), and by trypsin, chymotrypsin and acid protease at Stage III (25 DAH or 650 DD). This study provides new data on the digestive physiology of larval L. peru that are particularly pertinent to early weaning and nutritional physiology, and that may be useful in the larval culture of this species.

Gut Digestive Function and Microbiome after Correction of Experimental Dysbiosis in Rats by Indigenous Bifidobacteria.

In recent years, great interest has arisen in the use of autoprobiotics (indigenous bacteria isolated from the organism and introduced into the same organism after growing). This study aimed to evaluate the effects of indigenous bifidobacteria on intestinal microbiota and digestive enzymes in a rat model of antibiotic-associated dysbiosis. Our results showed that indigenous bifidobacteria (the Bf group) accelerate the disappearance of dyspeptic symptoms in rats and prevent an increase in chyme mass in the upper intestine compared to the group without autoprobiotics (the C1 group), but significantly increase the mass of chyme in the colon compared to the C1 group and the control group (healthy animals). In the Bf group in the gut microbiota, the content of opportunistic bacteria (Proteus spp., enteropathogenic Escherichia coli) decreased, and the content of some beneficial bacteria (Bifidobacterium spp., Dorea spp., Blautia spp., the genus Ruminococcus, Prevotella, Oscillospira) changed compared to the control group. Unlike the C1 group, in the Bf group there was no decrease in the specific activities of maltase and alkaline phosphatase in the mucosa of the upper intestine, but the specific activity of maltase was decreased in the colon chyme compared to the control and C1 groups. In the Bf group, the specific activity of aminopeptidase N was reduced in the duodenum mucosa and the colon chyme compared to the control group. We concluded that indigenous bifidobacteria can protect the microbiota and intestinal digestive enzymes in the intestine from disorders caused by dysbiosis; however, there may be impaired motor function of the colon.

Preparation of a Fucoidan-Grafted Hyaluronan Composite Hydrogel for the Induction of Osteoblast Differentiation in Osteoblast-Like Cells.

A suitable bone substitute is necessary in bone regenerative medicine. Hyaluronan (HA) has excellent biocompatibility and biodegradability and is widely used in tissue engineering. Additionally, research on fucoidan (Fu), a fucose- and sulfate-rich polysaccharide from brown seaweed, for the promotion of bone osteogenic differentiation has increased exponentially. In this study, HA and Fu were functionalized by grafting methacrylic groups onto the backbone of the chain. Methacrylate-hyaluronan (MHA) and methacrylate-fucoidan (MFu) were characterized by FTIR and 1H NMR spectroscopy to confirm functionalization. The degrees of methacrylation (DMs) of MHA and MFu were 9.2% and 98.6%, respectively. Furthermore, we evaluated the mechanical properties of the hydrogels formed from mixtures of photo-crosslinkable MHA (1%) with varying concentrations of MFu (0%, 0.5%, and 1%). There were no changes in the hardness values of the hydrogels, but the elastic modulus decreased upon the addition of MFu, and these mechanical properties were not significantly different with or without preosteoblastic MG63 cell culture for up to 28 days. Furthermore, the cell morphologies and viabilities were not significantly different after culture with the MHA, MHA-MFu0.5, or MHA-MFu1.0 hydrogels, but the specific activity and mineralization of alkaline phosphatase (ALP) were significantly higher in the MHA-MFu1.0 hydrogel group compared to the other hydrogels. Hence, MHA-MFu composite hydrogels are potential bone graft materials that can provide a flexible structure and favorable niche for inducing bone osteogenic differentiation.

A time course study on dose-response relationship between alcohol exposure and its effects on lipid profile and biomarkers of tissue damage

This present research investigated variations in lipid profiles and important biomarkers of tissue damage in response to graded concentrations of alcohol administration in male Wistar rats. Group A (control) received distilled water while group B, C and D received 30%, 40% and 50% (v/v) alcohol respectively. Five rats each from groups A-D were sacrificed after day(s) 1, 7, 14, 21 and 28 of administration. A significant increase was observed at day 28 for serum cholesterol by 79% (group B), 78% (group C) and 47% (group D) together with serum phospholipid 58% (group B), 50% (group C) and 92% (group D). Serum triacylglycerol increased by 71% (group B), 43% (group C) and 16% (group D) at day 21, while concentration of serum albumin decreased at day 28 by 40.9% (group B), 50.2% (group C), 53.3% (group D) respectively when compared with control (group A). Serum aminotransferases and alkaline phosphatase specific activities, as well as creatinine and uric acid concentration increased in a concentration-dependent manner, following alcohol administration. Though most of these effects induced by alcohol were time- and concentration-dependent, 40% alcohol appear to be more stable, giving results consistent with alcohol-induced damages, with minimal mortality. This study therefore further validated dyslipidemia and imbalance in clinical biomarkers as hallmarks of tissue damage induced by excessive alcohol consumption with an insight on the time- and concentration-response relationship between alcohol consumption and its toxicity.

Triggering cultured human osteoblast-like cells’ maturation by an extremely low magnitude alternating electromagnetic field

Introduction: Alternating and pulsed electromagnetic magnetic fields (AEMF and PEMF) of different amplitudes and frequencies can induce metabolic and proliferative effects in osteoblasts, but there is no clearly directed tendency of these effects. I hypothesize that there are extremely low triggering parameters of alternating electromagnetic field (EMF) intensity, i.e., above the background magnetic field on earth but below the lowest AEMF and PEMF that have been investigated to date (above 0.07 mT and below 0.4 mT) that induce cellular response. Methods: Accordingly, human monolayer explant culture replica were exposed four times in 24-hour intervals to two minutes of 10 kHz AEMF or PEMF (10 Hz pulses at a basic 5 kHz frequency) with a maximal EMF intensity of 0.2 mT for both. Cell proliferation was estimated from microscopic cell counting and cell death by lactate dehydrogenase (LDH) specific activity in culture media (measured using a colorimetric method). The early marker of osteoblast maturation, cellular alkaline phosphatase (AP) specific activity, was measured using a colorimetric method (n=6 for all experiment conditions). Results: No difference was found in cell numbers in the culture samples exposed either to AEMF or PEMF and in the LDH’s specific activity in culture media in comparison to the unexposed controls (p&gt;0.05, for both). The cellular AP’s specific activity increased significantly only in cell cultures exposed to the 10 kHz AEMF (p=0.011). Conclusions: The triggering for human osteoblast activation for maturation by an extremely low AEMF (10 kHz) is at least 0.2 mT, which is distinct and below the previously found triggering range of a PEMF for proliferation induction. Therefore, application of these EMF parameters in a clinical setup by a separate finetuning of osteoblast proliferation and maturation might have a therapeutic value in enhancing damaged bone regeneration.

Comparing bone tissue engineering efficacy of HDPSCs, HBMSCs on 3D biomimetic ABM-P-15 scaffolds in vitro and in vivo

Human bone marrow mesenchymal stem cells (HBMSCs) has been the gold standard for bone regeneration. However, the low proliferation rate and long doubling time limited its clinical applications. This study aims to compare the bone tissue engineering efficacy of human dental pulp stem cells (HDPSCs) with HBMSCs in 2D, and 3D anorganic bone mineral (ABM) coated with a biomimetic collagen peptide (ABM-P-15) for improving bone-forming speed and efficacy in vitro and in vivo. The multipotential of both HDPSCs and HBMSCs have been compared in vitro. The bone formation of HDPSCs on ABM-P-15 was tested using in vivo model. The osteogenic potential of the cells was confirmed by alkaline phosphatase (ALP) and immunohistological staining for osteogenic markers. Enhanced ALP, collagen, lipid droplet, or glycosaminoglycans production were visible in HDPSCs and HBMSCs after osteogenic, adipogenic and chondrogenic induction. HDPSC showed stronger ALP staining compared to HBMSCs. Confocal images showed more viable HDPSCs on both ABM-P-15 and ABM scaffolds compared to HBMSCs on similar scaffolds. ABM-P-15 enhanced cell attachment/spreading/bridging formation on ABM-P-15 scaffolds and significantly increased quantitative ALP specific activities of the HDPSCs and HBMSCs. After 8 weeks in vivo implantation in diffusion chamber model, the HDPSCs on ABM-P-15 scaffolds showed extensive high organised collagenous matrix formation that was positive for COL-I and OCN compared to ABM alone. In conclusion, the HDPSCs have a higher proliferation rate and better osteogenic capacity, which indicated the potential of combining HDPSCs with ABM-P-15 scaffolds for improving bone regeneration speed and efficacy.

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