Diosgenyl saponins possess a variety of biological functions. Herein, we demonstrate a new type of diosgenyl saponin derivatives that inhibit cellular proliferation of oral squamous cell carcinoma (OSCC) cell lines. Thereafter, we analyzed these cells' expression of apoptosis-related proteins. Crucial proteins that participate in apoptosis regulation including caspases 8, 9, and 3, and cleaved Bid were activated and upregulated accompanied by increased concentrations of diosgenyl saponins. Meanwhile, Bcl-2 was downregulated and mitochondrial membrane potential decreased. In our mice model of OSCC, compound 1 showed potent inhibition of solid tumor growth and salient antitumor activity. Diosgenyl ?-D-galactopyranosyl-(1?4)-?-D-glucopyranoside might induce OSCC cell line apoptosis through extrinsic and intrinsic pathways, and might provide a mechanistic background for the development of this new type of diosgenylsaponin derivatives into anti-oral cancer agents against OSCC.
Bio-electrospraying (BES) is a technique for directly jetting living cells that has significant implications for tissue engineering and regenerative medicine. However, the effect of BES on human adipose-derived stem cells (hASCs) remains unknown. Here, we show that an hASC suspension was successfully electrosprayed via a continuous, stable and linearly directed electrospray at 10 kV and at 3 ml/h. Morphological observations and Trypan Blue and CCK-8 assays revealed that the cells remained viable and proliferated at a rate similar to that of the controls (0 kV). However, at 20 kV, BES became unstable and cell viability was reduced. Moreover, hASCs electrosprayed at 10 kV retained their multilineage potential, successfully differentiating into chondrogenic, osteogenic and neurogenic lineages. Thus, BES does not significantly affect cell morphology, viability or multipotency.
Monoclonal antibody-conjugated sphere-shaped gold nanoparticles were combined with single-walled carbon nanotubes (SWCNTs) to create a nanohybrid system to selectively detect and eradicate multiple drug resistant Salmonella (MDRS) typhimurium DT104 bacteria. The Raman signal intensity from Rhodamine 6G (Rh6G) modified monoclonal AC04 antibody SWCNTs-gold nanoparticle (SWCNT-GNPs) hybrid provided a SERS enhancement by several orders of magnitude to detect the MDRS bacteria over the GNP system. A targeted photothermolysis experiment using 670 nm light at 2 W cm(-2) for 15 min, resulted in selective and irreparable damage to more than 99% Salmonella DT104 at the concentration of 10(5) CFU mL(-1). In comparison to solely SWCNTs or GNPs, our SWCNT-GNPs nanohybrids have also shown a better photothermal efficiency.
During the dental pulp repair process, human dental pulp cells (HDPCs) migrate to injury sites where they may differentiate into odontoblastlike cells. WNT6 plays a role in dental development and can activate a noncanonical pathway including the c-Jun N-terminal kinase (JNK) pathway. The mechanism of WNT6 in dental pulp repair is still unknown. The purpose of this study was to explore the potential role of the WNT6/JNK signaling pathway in the promotion of cell migration and the differentiation of HDPCs.
Electrospinning has been employed extensively in tissue engineering to generate nanofibrous scaffolds from either natural or synthetic biodegradable polymers. Three-dimensional electrospun scaffolds can create a multi-scale environment capable of facilitating cell adhesion, proliferation, and differentiation. One such multi-scale scaffold incorporates nanofibrous features to mimic the extracellular matrix along with a porous network for the regeneration of a variety of tissues. This review will discuss nanofibrous scaffolds and their tissue-engineering applications in bone, cartilage, periodontium, tooth, and incorporated drug delivery systems. Combination with other technologies, electrospun scaffolds can contribute to the field of craniofacial regeneration and advance technology for tissue-engineered replacements in many physiological systems in near future.
Recent studies have brought endothelial-mesenchymal transition (EndMT) as a special perspective of epithelial- mesenchymal transition (EMT) into eyes. Traditionally, EndMT is considered as a source for fibroblasts and myofibroblasts, and it is extensively investigated in physiologic cardiac development as well as in pathologic tumor and fibrosis. Recently, new studies have found that EndMT-transformed cells had 'stemness', which means they could differentiate into chondroblasts, osteoblasts, and adipoblasts in differential culture, respectively. This gives EndMT a bright application future in tissue engineering and regeneration, especially for the formation of cartilage and bone.
Disorders in articular cartilage affect many people, and are one of the leading causes of infirmity and decreased quality of life in adults. Tissue engineering and regenerative medicine related to cartilage include a broad range of settings and approaches that seek to repair, augment, replace or regenerate cartilage tissue. Formation of new tissue by cartilageforming cells (chondrogenic cells) is a central feature of each of these goals. Mesenchymal stem cell (MSC) transplantation has been introduced to avoid some of the side-effects and complications of current techniques. Different mesenchymal stem cell sources possess different abilitties to regenerate cartilage. However, the use of MSCs for cartilage repair is still at the stage of preclinical and phase I studies, and no comparative clinical studies have been reported. Therefore, it is difficult to make conclusions in human studies. The focus of this review is the role of MSCs, from different sources in which animal models were involved, in tissue-engineering cartilage repair, and research findings aimed at exploring a more rational application of animal models as the basis for future research, with clinical transformation providing a context.
In 2006, Takahashi and Yamanaka first established induced pluripotent stem cells (iPScs). Since then, numerous improvements have been made in the fields of stem cell research, drug research, modelling of diseases, and the treatment of degenerative diseases. Recently, there has been increasing research involving small molecules for evaluating the efficiency of iPSc generation and reducing the risks of heredity as well as oncogenous problems. However, the molecular mechanisms of iPScs remain to be further explored, to meet the demands of practical applications. With a better understanding of degenerative diseases, more complex treatment strategies for novel regenerative medicine are anticipated, and iPSc technology offers an available pathway. This review focuses on the development and application of iPScs.
Cartilage has poor ability of spontaneous repair. Traditional treatments such as microfracture, bone drilling and autologous osteochondral graft were not fully satisfactory to fulfill the clinical needs. The idea of mesenchymal stem cell (MSCs-based cartilage regeneration has been put forward for decades. Large number of studies have been conducted on the biological properties of MSCs, the factors which might facilitate chondrogenic differentiation of MSCs, as well as the scaffold materials for tissue engineering. Promising results have been reported for cartilage repair in animal models. But before massive clinical application of MSCs, more efforts are needed on: differentiation improvement toward mature cartilage chondrocytes instead of hypertrophic chondrocyes and in vitro/in vivo phenotype maintenance; engineering an ideal biomaterial, which can meet the needs of the cartilage regeneration; and performing more studies on critical defects of large animals.
The craniofacial region contains many specified tissues, including bone, cartilage, muscle, blood vessels, fat, skin and neurons. A defect or dysfunction of the craniofacial tissue after post-cancer ablative surgery, trauma, congenital malformations and progressive deforming skeletal diseases has a huge influence on the patient's life. Therefore, functional reconstruction of damaged tissues is highly sought. The use of cell-based therapies represents one of the most advanced methods for enhancing the regenerative response for craniofacial wound-healing. The recently acquired ability to reprogram human adult somatic cells to induced pluripotent stem cells (iPSCs) in culture may provide a powerful tool for in vitro disease modeling and an unlimited source for cell replacement therapy. This review focuses on the generation, biological characterization and discussion of the potential application of iPSCs for craniofacial tissue-engineering applications.
In this paper we describe how utilization of low molecular weight alginate-derived oligosaccharide (ADO) and chito-oligosaccharide (COS) in conjunction with antibiotics, could more effectively inhibit the growth of wild-type and resistant Pseudomonas aeruginosa. Inhibition is effected by modulating the bacteria's quorum sensing (QS) system, thus regulating biofilm formation and reducing resistance to antibiotic treatment. This can be demonstrated by using conventional MIC screening. COS showed synergistic effects with azithromycin, whereas ADO indicated additive effects against wild-type P. aeruginosa. Using electrospray-ionization mass spectroscopy (ESI-MS), matrix-assisted laser desorption/ionization-time of flightmass spectroscopy (MALDI-TOF-MS) and nuclear magnetic resonance (NMR), the chemical structure of ADO and of COS was characterized. The wild-type and resistant strains were identified by 16S rRNA sequence analysis. This report demonstrates the feasibility of attenuating the tolerance of P. aeruginosa to azithromycin by using specific marine oligosaccharides.
Adipose-derived stem cells (ASCs) have been discovered for more than a decade. Due to the large numbers of cells that can be harvested with relatively little donor morbidity, they are considered to be an attractive alternative to bone marrow derived mesenchymal stem cells. Consequently, isolation and differentiation of ASCs draw great attention in the research of tissue engineering and regenerative medicine. Cartilage defects cause big therapeutic problems because of their low self-repair capacity. Application of ASCs in cartilage regeneration gives hope to treat cartilage defects with autologous stem cells. In recent years, a lot of studies have been performed to test the possibility of using ASCs to re-construct damaged cartilage tissue. In this article, we have reviewed the most up-to-date articles utilizing ASCs for cartilage regeneration in basic and translational research. Our topic covers differentiation of adipose tissue derived mesenchymal stem cells into chondrocytes, increased cartilage formation by co-culture of ASCs with chondrocytes and enhancing chondrogenic differentiation of ASCs by gene manipulation.
Carbon nanotubes (CNT) are allotropes of carbon with a cylindrical nanostructure. They have recently aroused great interests as drug carriers, but their pharmacokinetic profiles which determine their potentials in clinical application are yet to be fully understood. Therefore, this overview attempts to outline the processes of absorption, distribution, metabolism and excretion (ADME) that govern the pharmacokinetics of CNT. In addition, the molecular mechanisms of intracellular internalization and drug release are also discussed.
Carbon nanotubes (CNTs) find their extensive application as a promising material in medicine due to unique characteristics. However, such materials have been accompanied with potentially hazardous effects on human health. The toxicity of CNTs may vary depending on their structural characteristics, surface properties and chemical composition. To gain insight into the toxicity of CNTs in vivo and in vitro, we summarize contributing factors for the toxic effects of CNTs in this review. In addition, we elaborate on the toxic effects and mechanisms in target sites at systemic, organic, cellular, and biomacromolecule levels. Various issues are reported to be effected when exposed to CNTs including (1) blood circulation, (2) lymph circulation, (3) lung, (4) heart, (5) kidney, (6) spleen, (7) bone marrow, and (8) blood brain barrier. Though there have been published reports on the toxic effects of CNTs to date, more studies will still be needed to gain full understanding of their potential toxicity and underlying mechanisms.
Carbon nanotubes have shown broad potential in biomedical applications, given their unique mechanical, optical, and chemical properties. Functionalized carbon nanotubes not only can deliver drug into specific organs but also can inherently produce heating by near-infrared laser radiation for cancer therapy. However, the toxicological and pharmacological profile of such carbon nanotube system will have to be determined prior to any clinical study undertaken. For providing a guide to develop safe drug carriers, this review discusses the functionalization, toxicity and pharmacokinetics of carbon nanotubes. Lastly, the drug delivery and thermal ablation on carbon nanotubes are proposed.
In recent years, nanotechnology research has made great strides in the area of pharmacy, especially for drug delivery systems. Polymeric nanoparticles provide significant stability in anti-neoplastic drug research and have demonstrated the ability to solve the problems of therapeutic efficacy and diagnostic sensitivity. In this review, we describe the specific advantages of polymeric nanoparticles and their applications for a drug delivery system. The latest research on PHA-based polymeric nanoparticles and PLGA is also discussed.
Nanomaterials possess enormous potential for biomedical applications, while some of the most promising nanomaterials currently under investigation demonstrate prolonged tissue retention and contain heavy metals. This article investigates the pharmacokinetics of magnetic nanoparticles (MNPs) to help identify promising candidates with optimal pharmacokinetics and clearance from the body for biomedical use and synthesize nanomaterials ideal for biomedical use. The term magnetic nanoparticles (MNPs) refers to nanoparticles with ferromagnetism. Such nanoparticles have special characteristics, and many in the field of biological field have undertaken research involving, e.g., immobilized enzymes and proteins, biological cells, macromolecular separation, drug carriers, and targeted, immune, biological sensors.
Adipose-derived stem cells (ASCs) have been defined as cells that undergo sustained in vitro growth and have multilineage differentiation potential. However, the identity and purification of ASCs has proved elusive due to the lack of specific markers and poor understanding of their physiological roles. Here, we prospectively isolated and identified a restricted homogeneous subpopulation of ASCs (Lin(-)CD271(+)Sca-1(+)) from mouse adipose tissues on the basis of cell-surface markers. Individual ASCs generated colony-forming unit-fibroblast at a high frequency and could differentiate into adipocytes, osteoblasts, and chondrocytes in vitro. Expansion of ASCs in a large quantity was feasible in medium supplemented with fibroblast growth factor-2 and leukemia inhibitory factor, without loss of adipogenic and osteogenic differentiation capacity. Moreover, we found that the transplanted ASCs can differentiate into adipocytes in adipogenic microenvironment in vivo and osteoblasts in osteogenic microenvironment in vivo. Thus we proved that Lin, CD271, and Sca-1 could be used as the specific markers to purify ASCs from adipose tissue. The method we established to identify ASCs as defined in vivo entities will help develop ASCs transplantation as a new therapeutic strategy for bone regeneration and adipose tissue regeneration in clinic.
Graphene possesses a wide range of potential biomedical applications because of the unique physical and chemical properties. However, the side effects of grapheme and its derivatives on a number of biological models even on human body are still not very clear. Therefore, to properly assess the potential risk of grapheme and its derivatives, we summarize the current state of academic knowledge on their toxicity.
As the number of applications of quantum dots (QDs) grows, the likelihood of exposure increases. Because these metals have the potential for detrimental environmental and health effects, concerns have been raised over our lack of understanding about the fate of these products. Among various types of QDs, cadmium-based quantum dots attract the greatest attention due to their wide applications. To properly assess the potential risk of cadmium-containing QDs, we summarize the current state of academic knowledge on the toxicity of cadmium-based QDs.
Wnt5a plays an essential role in tissue development by regulating cell migration, though the molecular mechanisms are still not fully understood. Our study investigated the pathways involved in Wnt5a-dependent cell motility during the formation of dentin and pulp. Over-expression of Wnt5a promoted cell adhesion and formation of focal adhesion complexes (FACs) in human dental papilla cells (hDPCs), while inhibiting cell migration. Instead of activating the canonical Wnt signal pathway in hDPCs, Wnt5a stimulation induced activation of the JNK signal in a RhoA-dependent or independent manner. Inhibiting JNK abrogated Wnt5a-induced FACs formation but not cytoskeletal rearrangement. Both dominant negative RhoA (RhoA T19N) and constitutively active RhoA mutants (RhoA Q63L) blocked the Wnt5a-dependent changes in hDPCs adhesion, migration and cytoskeletal rearrangement here too, with the exception of the formation of FACs. Taken together, our study suggested that RhoA and JNK signaling have roles in mediating Wnt5a-dependent adhesion and migration in hDPCs, and the Wnt5a/JNK pathway acts both dependently and independently of the RhoA pathway.
Recent research has shown that adipose tissues contain abundant MSCs (mesenchymal stem cells). The origin and location of the adipose stem cells, however, remain unknown, presenting an obstacle to the further purification and study of these cells. In the present study, we aimed at investigating the origins of adipose stem cells. ?-SMA (?-smooth muscle actin) is one of the markers of pericytes. We harvested ASCs (adipose stromal cells) from ?-SMA-GFP (green fluorescent protein) transgenic mice and sorted them into GFP-positive and GFP-negative cells by FACS. Multilineage differentiation tests were applied to examine the pluripotent ability of the ?-SMA-GFP-positive and -negative cells. Immunofluorescent staining for ?-SMA and PDGF-R? (platelet-derived growth factor receptor ?) were applied to identify the ?-SMA-GFP-positive cells. Then ?-SMA-GFP-positive cells were loaded on a collagen-fibronectin gel with endothelial cells to test their vascularization ability both in vitro and in vivo. Results show that, in adipose tissue, all of the ?-SMA-GFP-positive cells congregate around the blood vessels. Only the ?-SMA-GFP-positive cells have multilineage differentiation ability, while the ?-SMA-GFP-negative cells can only differentiate in an adipogenic direction. The ?-SMA-GFP-positive cells maintained expression of ?-SMA during multilineage differentiation. The ?-SMA-GFP-positive cells can promote the vascularization of endothelial cells in three-dimensional culture both in vitro and in vivo. We conclude that the adipose stem cells originate from perivascular cells and congregate around blood vessels.
The goal of our research was to look into the clinical traits and genetic mutations in nonsyndromic oligodontia in a Chinese family and to gain insight into the role of mutations of PAX9, MSX1 and AXIN2 in oligodontia phenotypes.
Enzymatic digestion, the commonly used method of adipose-derived stromal cells isolation, is time consuming and expensive, especially when applied to large volumes of tissue. In the present study, the characteristics of the cells obtained by adipose tissue explant culture were studied. We found that adipose tissue fragments could adhere onto the growth surface of flasks in a very short time after plating and that fibroblast-like cells migrated from the explants and reached confluence. Morphologic analysis and surface markers expression suggested the mesenchymal origin of the cells derived from adipose tissue explants. After in vitro expansion these cells were successfully induced into adipogenic, osteogenic, and chondrogenic lineages, which demonstrated their multipotency. The high growth rate and colony-forming efficiency of explant-derived cells were similar to those of cells obtained by digestion. Furthermore, explant culture gave higher yield of cells than digestion method after primary culture. The experiment of ectopic adipogenesis in nude mice suggested the prospects for tissue engineering of these cells. In conclusion, we obtained multipotent stromal cells from adipose tissue by explant culture, and this method was simple, time saving, and gave a high yield of cells. Therefore, explant culture can be used as an effective way to isolate adipose-derived stromal cells for tissue engineering.
Mechanical forces play critical roles in the development and remodelling process of bone. As an alternative cell source for bone engineering, adipose-derived stem cells (ASCs) should be fully investigated for their responses to mechanical stress and the mechanisms responsible for osteogenic induction in response to mechanical signals.
This study was conducted to investigate whether in vitro chondrogenic differentiated human adipose-derived stem cells (hASCs) can maintain the chondrogenic phenotype in (3-hydroxybutrate-co-3-hydroxyvalerate) (PHBV) scaffolds and whether differentiated hASCs/PHBV construct can produce neocartilage in a heterotopic animal model. hASCs were cultured with or without chondrogenic media in vitro and then seeded on PHBV foams. Differentiated cell/PHBV constructs were subcutaneously implanted in nude mice for 8 or 16 weeks; nondifferentiated cell/PHBV constructs were implanted in the control group. The results in the control group showed no cartilage formation and the disappearance of the scaffold at 8 weeks. Conversely, all differentiated hASCs/PHBV implants kept their original shape throughout 16 weeks. These implants at 16 weeks had stronger chondrocytes-specific histochemical staining than those at 8 weeks, with GAG, total collagen, and compressive moduli increased with implantation time. Cartilage lacunae were observed in all retrieved implants at 16 weeks. The chondrocytes-specific genes were detected by RT-PCR at 16 weeks. The remnants of PHBV were observed in the implants throughout 16 weeks. This study demonstrates that chondrogenic predifferentiated hASCs have the ability to maintain a chondrogenic phenotype in PHBV and that cell/PHBV constructs can produce neocartilage in a heterotopic site, but the degradation rates of PHBV in different environments needs more investigation.
Clinical protocols utilize bone marrow to seed synthetic and decellularized allogeneic bone grafts for enhancement of scaffold remodeling and fusion. Marrow-derived cytokines induce host neovascularization at the graft surface, but hypoxic conditions cause cell death at the core. Addition of cellular components that generate an extensive primitive plexus-like vascular network that would perfuse the entire scaffold upon anastomosis could potentially yield significantly higher-quality grafts. We used a mouse model to develop a two-stage protocol for generating vascularized bone grafts using mesenchymal stem cells (hMSCs) from human bone marrow and umbilical cord-derived endothelial cells. The endothelial cells formed tube-like structures and subsequently networks throughout the bone scaffold 4-7 days after implantation. hMSCs were essential for stable vasculature both in vitro and in vivo; however, contrary to expectations, vasculature derived from hMSCs briefly cultured in medium designed to maintain a proliferative, nondifferentiated state was more extensive and stable than that with hMSCs with a TGF-beta-induced smooth muscle cell phenotype. Anastomosis occurred by day 11, with most hMSCs associating closely with the network. Although initially immature and highly permeable, at 4 weeks the network was mature. Initiation of scaffold mineralization had also occurred by this period. Some human-derived vessels were still present at 5 months, but the majority of the graft vasculature had been functionally remodeled with host cells. In conclusion, clinically relevant progenitor sources for pericytes and endothelial cells can serve to generate highly functional microvascular networks for tissue engineered bone grafts.
As the most important organs of occlusion, teeth are subjected to a variety of mechanical stresses. These stresses are transmitted into the dental pulp tissue and affect the dental pulp stem cells. In this study, human dental pulp stem cells were isolated from human impacted third molars and their multilineage differentiation abilities were tested. Human dental pulp stem cells were then exposed to cyclic tensile stretch. The results showed that the cyclic tensile stretch inhibited the expression of osteogenic marker genes and proteins such as BMP-2, OCN and ALP. Simultaneously, odontogenic marker genes and proteins such as DSPP, DSP and BSP were also inhibited by the mechanical stress. It was concluded that cyclic tensile stretch inhibits the osteogenic and odontogenic differentiation of dental pulp stem cells.
As a gamma-secretase inhibitor, DAPT has been widely used to evaluate the biological behaviors and Notch signaling pathway in various cells. This study was aimed to examine the effects of DAPT on the growth and vitamin D(3) induced osteogenesis in adipose derived stem cells (ASCs). The cells were treated with or without DAPT and induced to osteoblastic lineage in the presence of vitamin D(3). Alizarin red staining and real-time PCR results indicated that the addition of DAPT to vitamin D(3) treatments enhanced osteogenesis in ASCs. According to the fold increase and colony-forming unit assay results, the cells cultured in DAPT exhibited lower proliferation rate than those cultured in control medium. Hey1, expressed in the nucleus of ASCs to act as a transcriptional repressor, was downregulated when Notch signaling was inhibited by DAPT. Whereas the expression of Runx2 increased in the nucleus of osteogenic induced ASCs after DAPT treatment. This study demonstrated that DAPT reduced the proliferation and enhanced the osteogenesis in ASCs via regulation of Notch and Runx2 expression.
Osteogenic induction was regarded as an indispensable step for adipose-derived stromal cells (ADSCs) to have osteogenic ability. Non-induced ADSCs can also produce bone in vivo and heal skeletal defects. The present study aimed to compare the bone-forming ability of osteogenically induced ADSCs and non-induced ADSCs in vivo. Tissue-engineered constructs were prepared from osteogenically induced or non-induced ADSCs and porous hydroxyapatite/beta-tricalcium phosphate scaffolds. A scaffold without cells and an empty defect group were used as control. All were implanted in rat critical calvarial defects. After implantation for 6 and 12 weeks, bone formation was analyzed using histomorphometry and microcomputed tomography; there were no significant differences in the formation of new bone between osteogenically induced ADSCs and non-induced ADSCs (P > 0.05). In conclusion, osteogenic induction of ADSCs is not an indispensable step for bone formation in vivo. Non-induced ADSCs can also be used as seeding cells to construct bone tissue.
The goal of this retrospective study was to evaluate the efficacy of panfacial fracture repair and to review guidelines for treatment based on AO/Arbeitsgemeinschaft fuer Osteosynthesefragen Association for Study of Internal Fixation theories of biological osteosynthesis. Sixty-eight patients with panfacial fractures were subjected to preoperative X-ray cephalometric analysis and model surgery, followed by open surgical reduction, rigid internal fixation and at least 8 weeks of clinical follow up. A variety of surgical approaches were used, with the 68 patients undergoing a total of 93 surgical procedures. In all but eight patients, the treatment produced satisfactory correction of maxillofacial deformities and restoration of normal function. Among the eight patients whose treatment was not deemed successful, there were two whose facial deformities were not corrected by treatment. In addition, there were five patients with enophthalmos or motor disturbance of the eye that failed to show improvement during the study, and four patients who exhibited signs of limited mouth opening and malocclusion. The systematic and sequential choices of surgical methods were key factors in determining panfacial fracture treatment outcomes. We propose that treatment of bone fractures must take into account the biological characteristics of the damaged bone to facilitate selection of appropriate plate and screw systems and repositioning methods.
Pericytes are essential to vascularization, but the purification and characterization of pericytes remain unclear. Smooth muscle actin alpha (alpha-SMA) is one marker [corrected] of pericytes. The aim of this study is to purify the alpha-SMA positive cells from bone marrow and study the characteristics of these cells and the interaction between alpha-SMA positive cells and endothelial cells. The bone marrow stromal cells were harvested from alpha-SMA-GFP transgenic mice, and the alpha-SMA-GFP positive cells were sorted by FACS. The proliferative characteristics and multilineage differentiation ability of the alpha-SMA-GFP positive cells were tested. A 3-D culture model was then applied to test their vascularization by loading alpha-SMA-GFP positive cells and endothelial cells on collagen-fibronectin gel. Results demonstrated that bone marrow stromal cells are mostly alpha-SMA-GFP positive cells which are pluripotent, and these cells expressed alpha-SMA during differentiation. The alpha-SMA-GFP positive cells could stimulate the endothelial cells to form tube-like structures and subsequently robust vascular networks in 3-D culture. In conclusion, the bone marrow derived pluripotent cells include [corrected] pericytes and can contribute to vascularization.
Mesenchymal stem cells (MSCs) provide us an excellent cellular model to uncover the molecular mechanisms underlying adipogenic differentiation of adult stem cells. PPARgamma had been considered as an important molecular marker of cells undergoing adipogenic differentiation. Here, we demonstrated that expression and phosphorylation of PPARgamma could be found in bone marrow-derived MSCs cultured in expansion medium without any adipogenic additives (dexamethasone, IBMX, insulin or indomethacin). Then, PPARgamma was dephosphorylated in MSCs during the process of adipogenic differentiation. We then found that inhibition of MEK activation by specific inhibitor (PD98059) counteracted the PPARgamma expression and phosphorylation. However, expression and phosphorylation of PPARgamma did not present in MSCs cultured in medium with lower serum concentration. When these MSCs differentiated into adipocytes, no phosphorylation could be detected to accompany the expression of PPARgamma. Moreover, exposure of MSCs to higher concentration of serum induced stronger PPARgamma expression, and subsequently enhanced their adipogenesis. These data suggested that activation of the MEK/ERK signalling pathway by high serum concentration promoted PPARgamma expression and phosphorylation, and subsequently enhanced adipogenic differentiation of MSCs.
A large number of studies and clinical cases show that an ideal prognosis for mouth function cannot be obtained without sufficient and reasonable postsurgical functional exercise after jaw fracture. However, no unifying criteria exist on postsurgical functional exercise with jaw fracture. The study was designed to explore effective methods of postsurgical functional exercise of jaw fracture.
A case of Langerhans cell histiocytosis of the mandible was reported. A 34-year-old woman presented with pain for one year on the gingival of the low left jaw, and together with pyorrhea in the past 2 months. The histopathology and immunohistochemical examination confirmed the diagnosis of Langerhans cell histiocytosis.
In recent years, many researchers have paid more and more attentions on the use of Nanotechnology. Solid lipid nanoparticles (SLNs) are emerged as a promising alternation herein to emulsions, liposomes, microparticles and polymeric nanoparticles for their advantages. As promising drug carrier systems, SLNs are valuable for nanomedicine and have been widely used as delivery systems mostly for drugs and macromolecules like proteins, oligonucleotides and DNA by various application routes, such as intravenous, oral, duodenalous, intramuscular, pulmonary, intranasal, ocular, rectal and intraperitoneal administrations. It has been shown that SLNs can increase bioavailability, alter pharmacokinetic parameters and tissue distribution of the drug loaded. In this review, we will primarily focus on the absorption, pharmacokinetics and disposition properties of SLNs for their possible applications in drug delivery.
Nowadays, biodegradable nanoscale preparations such as liposomes, micelles, nanoparticles (NPs), and solid lipid nanoparticles (SLN) have attracted increasing attention from major researchers. Meanwhile the biosafety of the nanomaterials brings more and more attention. Toxicity of the biodegradable nanoscale preparations varies depending on their particle size, shape, surface structure, etc. This article aims to review the toxicity of the above-mentioned nanoscale preparations and the relative methodology. It may be significant for successful use of more nanoscale preparations in clinical practice.
Nowadays, biodegradable nanoscale preparations such as liposomes, micelles, nanoparticles (NPs), and solid lipid nanoparticles (SLN) have attracted increasing attention from major researchers. This article aims to review the absorption, pharmacokinetics, distribution properties and toxicity of the above-mentioned nanoscale preparations and the relative methodology. It may be significant for successful use of more nanoscale preparations in clinical practice.
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