|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Differential effect of ECM molecules on re-expression of cartilaginous markers in near quiescent human chondrocytes. J Cell Physiol. 2010 Dec 16; Authors: Chiu LH, Chen SC, Wu KC, Yang CB, Fang CL, Lai WF, Tsai YH The limited source of healthy primary chondrocytes restricts the clinical application of tissue engineering for cartilage repair. Therefore, method to maintain or restore the chondrocyte phenotype during in vitro expansion is essential. The objective of this study is to establish the beneficial effect of ECM molecules on restoring the re-expression of cartilaginous markers in primary human chondrocytes after extensive monolayer expansion. During the course of chondrocyte serial expansion, COL2A1, SOX9, and AGN mRNA expression levels, and GAG accumulation level were reduced significantly in serially passaged cells. Exogenous type II collagen dose-dependently elevated GAG level and induced the re-expression of cartilaginous marker mRNAs in P7 chondrocytes. Chondroitin sulfate did not show significant effect on P7 chondrocytes, while hyaluronic acid inhibited the expression of SOX9 and AGN mRNAs. Upon treatment with type II collagen, FAK, ERK1/2, and JNK were activated via phosphorylation in P7 chondrocytes within 15 minutes. Furthermore, GFOGER integrin blocking peptide, MEK inhibitor and JNK inhibitor, not p38 inhibitor, significantly reduced the type II collagen-induced GAG deposition level. Finally, in the presence of TGF-β1 and IGF-I, P7 chondrocytes cultured in 3D type II collagen matrix exhibited better cartilaginous features than those cells cultured in the type I collagen matrix. In conclusion, type II collagen alone can effectively restore cartilaginous features of expanded P7 human chondrocytes. It is probably mediated via the activation of FAK-ERK1/2 and FAK-JNK signaling pathways. The potential application of type II collagen in expanding a scarcity of healthy chondrocytes in vitro for further tissue engineering is implicated. © 2010 Wiley-Liss, Inc. PMID: 21165913 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | 3 hours of perfusion culture prior to 28 days of static culture, enhances osteogenesis by human cells in a collagen GAG scaffold. Biotechnol Bioeng. 2010 Dec 16; Authors: Keogh MB, Partap S, Daly JS, O' Brien FJ In tissue engineering bioreactors can be used to aid in the in vitro development of new tissue by providing biochemical and physical regulatory signals to cells and encouraging them to undergo differentiation and/or to produce extracellular matrix prior to in vivo implantation. This study examined the effect of short term flow perfusion bioreactor culture, prior to long term static culture, on human osteoblast cell distribution and osteogenesis within a collagen glycosaminoglycan (CG) scaffold for bone tissue engineering. Human Foetal Osteoblasts (hFOB 1.19) were seeded onto CG scaffolds and pre-cultured for 6 days. Constructs were then placed into the bioreactor and exposed to 3×1hr bouts of steady flow (1ml/min) separated by 7hrs of no flow over a 24hr period. The constructs were then cultured under static osteogenic conditions for up to 28 days. Results show that the bioreactor and static culture control groups displayed similar cell numbers and metabolic activity. Histologically however, peripheral cell-encapsulation was observed in the static controls, whereas, improved migration and homogenous cell distribution was seen in the bioreactor groups. Gene expression analysis showed that all osteogenic markers investigated displayed greater levels of expression in the bioreactor groups compared to static controls. While static groups showed increased mineral deposition; mechanical testing revealed that there was no difference in the compressive modulus between bioreactor and static groups. In conclusion, a flow perfusion bioreactor improved construct homogeneity by preventing peripheral encapsulation whilst also providing an enhanced osteogenic phenotype over static controls. © 2010 Wiley Periodicals, Inc. PMID: 21165906 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mathieu beams as versatile light moulds for 3D micro particle assemblies. Opt Express. 2010 Dec 6;18(25):26084-91 Authors: Alpmann C, Bowman R, Woerdemann M, Padgett M, Denz C We present tailoring of three dimensional light fields which act as light moulds for elaborate particle micro structures of variable shapes. Stereo microscopy is used for visualization of the 3D particle assemblies. The powerful method is demonstrated for the class of propagation invariant beams, where we introduce the use of Mathieu beams as light moulds with non-rotationally-symmetric structure. They offer multifarious field distributions and facilitate the creation of versatile particle structures. This eneral technique may find its application in micro fluidics, chemistry, biology, and medicine, to create highly efficient mixing tools, for hierarchical supramolecular organization or in 3D tissue engineering. PMID: 21164957 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue Engineering Penoplasty with Biodegradable Scaffold Maxpol-T Co-Grafted Autologous Fibroblasts for Small Penis Syndrome. J Androl. 2010 Dec 16; Authors: Jin Z, Wu YG, Yuan YM, Peng J, Gong YQ, Li GY, Song WD, Cui WS, He XY, Xin ZC In this study, we investigated the safety and efficacy of a Poly acid-co-Glycolide (PLGA) biodegradable scaffold (Maxpol-T) coated by autologous fibroblasts (AF) for penile girth enlargement in small penis syndrome (SPS). Eighty patients with SPS were enrolled in a clinical study at two medical centers; 69 patients completed the study protocol. Scrotal skin was harvested under local anesthesia and the AF were cultured and seeded on a Maxpol-T scaffold; the co-grafted scaffold was implanted under the Buck's fascia of penile shaft via a circumcising incision. Patients were followed up at 1, 3, and 6 months to evaluate penile girth changes. Patient satisfaction was assessed via Visual Analogue Scale (VAS) and score on the International Index of Erection Function Erectile Function Domain (IIEF5). Mean preoperative penile girth in the flaccid and erect state was 8.18 ± 0.83cm and 10.26 ± 1.22cm respectively. At the 6 month post operative follow-up mean penile girth in the flaccid and erect state was increased to 12.19 ± 1.27 cm and 13.18 ± 1.31 cm, respectively (p < 0.001 for change in both flaccid and erect state). Sixty-five patients (94.2%) reported satisfaction with the procedure. Among them, 4 cases (5.8%) were dissatisfied, 7 cases (10.1%) were satisfied, 26 cases (37.7%) were very satisfied and 32 cases (46.4%) were extremely satisfied. All men maintained IIEF-5 scores > 22. Complications included prolonged subcutaneous edema in 3 patients (4.3%) and pinpoint erosion at the suture area in 3 patients (4.3%). Implantation of autologous fibroblasts seeded on a Maxpol-T collagen scaffold holds promise as a safe and novel technique for penile girth enhancement in patients with small penis syndrome. PMID: 21164145 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The interactions of astrocytes and fibroblasts with defined pore structures in static and perfusion cultures. Biomaterials. 2010 Dec 14; Authors: Sun T, Donoghue PS, Higginson JR, Gadegaard N, Barnett SC, Riehle MO Open pores to maintain nutrient diffusion and waste removal after cell colonization are crucial for the successful application of constructs based on assembled membranes, in our case tubular scaffolds made of ɛ-polycaprolactone (PCL), for use in tissue engineering. Due to the complex three-dimensional structure and large size of such scaffolds needed for transplantable tissues, it is difficult to investigate the cell-pore interactions in situ. Therefore miniaturized bioreactors inside Petri dishes (30 mm in diameter), containing porous PCL or poly-dimethylsiloxane (PDMS) membranes, were developed to allow the interactions of different cells with defined pores to be investigated in situ during both static and perfusion cultures. Investigation of two different cell types (fibroblasts and cortical astrocytes) and how they interact with a range of pores (100-350 μm in diameter) for up to 50 days indicated that the cells either 'covered' or 'bridged' the pores. Three distinct behaviors were observed in the way cortical astrocytes interacted with pores, while fibroblasts were able to quickly bridge the pores based on consistent "joint efforts". Our studies demonstrate that the distinct pore sealing behaviors of both cell types were influenced by pore size, initial cell density and culture period, but not by medium perfusion within the range of shear forces investigated. These findings form important basic data about the usability of pores within scaffolds that could inform the design and fabrication of suitable scaffolds for various applications in tissue engineering. PMID: 21163522 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Induced pluripotent stem cells: advances to applications. Stem Cells Cloning. 2010 Jan 1;3:29-37 Authors: Nelson TJ, Martinez-Fernandez A, Yamada S, Ikeda Y, Perez-Terzic C, Terzic A Induced pluripotent stem cell (iPS) technology has enriched the armamentarium of regenerative medicine by introducing autologous pluripotent progenitor pools bioengineered from ordinary somatic tissue. Through nuclear reprogramming, patient-specific iPS cells have been derived and validated. Optimizing iPS-based methodology will ensure robust applications across discovery science, offering opportunities for the development of personalized diagnostics and targeted therapeutics. Here, we highlight the process of nuclear reprogramming of somatic tissues that, when forced to ectopically express stemness factors, are converted into bona fide pluripotent stem cells. Bioengineered stem cells acquire the genuine ability to generate replacement tissues for a wide-spectrum of diseased conditions, and have so far demonstrated therapeutic benefit upon transplantation in model systems of sickle cell anemia, Parkinson's disease, hemophilia A, and ischemic heart disease. The field of regenerative medicine is therefore primed to adopt and incorporate iPS cell-based advancements as a next generation stem cell platforms. PMID: 21165156 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In vitro assays misrepresent in vivo lineage potentials of murine lymphoid progenitors. Blood. 2010 Dec 16; Authors: Ehrlich LI, Serwold T, Weissman IL The identity of T cell progenitors that seed the thymus has remained controversial, largely because many studies differ over whether these progenitors retain myeloid potential. Contradictory reports diverge in their use of various in vitro and in vivo assays. In order to consolidate these discordant findings, we compared the myeloid potential of two putative thymus seeding populations (CLP and MPP), and the earliest intrathymic progenitor (DN1), using two in vitro assays and in vivo readouts. These assays gave contradictory results: CLP and DN1 displayed surprisingly robust myeloid potential on OP9-DL1 in vitro stromal co-cultures, but displayed little myeloid potential in vivo, as well as in methylcellulose cultures. MPP, on the other hand, displayed robust myeloid potential in all settings. We conclude that stromal co-cultures reveal cryptic, but nonphysiologic myeloid potentials of lymphoid progenitors, providing an explanation for contradictory findings in the field, and underscoring the importance of using in vivo assays for the determination of physiologic lineage potentials. PMID: 21163922 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Novel soybean/gelatine-based bioactive and injectable hydroxyapatite foam: material properties and cell response. Acta Biomater. 2010 Dec 13; Authors: Perut F, Montufar EB, Ciapetti G, Santin M, Salvage J, Traykova T, Planell JA, Ginebra MP, Baldini N Despite their ascertain osteoconductivity, clinical use of calcium phosphate cements is limited both by their relatively slow rate of resorption and by the lack of rheological properties compatible with injectability. Bone in-growth and material resorption have been improved by the development of porous calcium phosphate cements. However, injectable formulations have so far been obtained only through the addition of relatively toxic surfactants. The present work describes the osteoblast response to a novel injectable, foamed bone cement based on a composite formulation including the bioactive foaming agents soybean and gelatine. Foaming properties of both de-fatted soybean and gelatine gels were exploited to develop a self-hardening soy/gelatin/hydroxyapatite composite foam able to retain porosity upon injection. After setting, the foamed paste produced a calcium-deficient hydroxyapatite scaffold, showing good injectability and cohesion as well as interconnected porosity after injection. The intrinsic bioactivity of soybean and gelatine was shown to favour osteoblast adhesion and growth. These findings suggest that injectable, porous and bioactive calcium phosphate cements can be produced for bone regeneration through minimally-invasive surgery. PMID: 21163370 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Granulocyte-colony stimulating factor drives the in vitro differentiation of human dendritic cells that induce anergy in naïve T cells. Eur J Immunol. 2010 Nov;40(11):3097-106 Authors: Rossetti M, Gregori S, Roncarolo MG G-CSF is a modulator of T-cell and DC functions. Previous reports show that monocytes from G-CSF-treated (post-G) healthy donors differentiate into tolerogenic DC in vitro in the presence of autologous serum, containing high levels of IL-10 and IFN-α, and in turn induce type 1 Treg (Tr1) cells. However, the direct effect of G-CSF on DC differentiation was not investigated. Here, we show that monocytes differentiated in the presence of exogenous G-CSF (G-DC) remain CD14(+) CD1a(-) , but acquire a DC-like morphology, express CD83 and CD86 and low levels of the tolerogenic markers Ig-like transcript (ILT)4 and HLA-G. G-DC spontaneously produce IL-10 and, upon stimulation, low levels of IL-12. G-DC display low stimulatory capacity and induce anergy in naïve T cells, but do not confer suppressive function. Therefore, in vitro differentiation of monocyte-derived DC in the presence of G-CSF can replicate some but not all features of post-G DC. These findings indicate that the tolerogenic properties of G-CSF do not exclusively reside in its direct effect on DC, which in turn induce T-cell anergy, but also in its ability to generate a tolerogenic milieu in vivo, which is necessary for Tr1 cell induction and cannot be replicated in vitro. PMID: 20957751 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | In Delicate Balance: Stem Cells and Spinal Cord Injury Advocacy. Stem Cell Rev. 2010 Dec 14; Authors: Parke S, Illes J Spinal cord injury (SCI) is a major focus for stem cell therapy (SCT). However, the science of SCT has not been well matched with an understanding of perspectives of persons with SCI. The online advocacy community is a key source of health information for primary stakeholders and their caregivers. In this study, we sought to characterize the content of SCI advocacy websites with respect to their discussion of SCT and stem cell tourism. We performed a comprehensive analysis of SCI advocacy websites identified through a web search and verified by expert opinion. Two independent researchers coded the information for major themes (e.g., scientific & clinical facts, research & funding, policy, ethics) and valence (positive, negative, balanced, neutral). Of the 40 SCI advocacy websites that met inclusion criteria, 50% (N=20) contained information about SCT. Less than 18% (N=7) contained information on stem cell tourism. There were more than ten times as many statements about SCT with a positive valence (N=67) as with a negative valence (N=6). Ethics-related SCT information comprised 20% (N=37) of the total content; the largest proportion of ethics-related content was devoted to stem cell tourism (80%, N=30 statements). Of those, the majority focused on the risks of stem cell tourism (N=16). Given the still-developing science behind SCT, the presence of cautionary information about stem cell tourism at advocacy sites is ethically appropriate. The absence of stem cell tourism information at the majority of advocacy sites represents a lost educational opportunity. PMID: 21161442 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Medical Tourism Services Available to Residents of the United States. J Gen Intern Med. 2010 Dec 15; Authors: Alleman BW, Luger T, Reisinger HS, Martin R, Horowitz MD, Cram P BACKGROUND: There are growing reports of United States (US) residents traveling overseas for medical care, but empirical data about medical tourism are limited. OBJECTIVE: To characterize the businesses and business practices of entities promoting medical tourism and the types and costs of procedures being offered. DESIGN, PARTICIPANTS, AND OUTCOMES: Between June and August 2008, we conducted a telephone survey of all businesses engaged in facilitating overseas medical travel for US residents. We collected information from each company including: the number of employees; number of patients referred overseas; medical records security processes; destinations to which patients were referred; treatments offered; treatment costs; and whether patient outcomes were collected. RESULTS: We identified 63 medical tourism companies and 45 completed our survey (71%). Companies had a mean of 9.8 employees and had referred an average of 285 patients overseas (a total of approximately 13,500 patients). 35 (79%) companies reported requiring accreditation of foreign providers, 22 (50%) collected patient outcome data, but only 17 (39%) described formal medical records security policies. The most common destinations were India (23 companies, 55%), Costa Rica (14, 33%), and Thailand (12, 29%). The most common types of care included orthopedics (32 companies, 73%), cardiac care (23, 52%), and cosmetic surgery (29, 66%). 20 companies (44%) offered treatments not approved for use in the US - most commonly stem cell therapy. Average costs for common procedures, CABG ($18,600) and knee arthroplasty ($10,800), were similar to previous reports. CONCLUSIONS: The number of Americans traveling overseas for medical care with assistance from medical tourism companies is relatively small. Attention to medical records security and patient outcomes is variable and cost-savings are dependent on US prices. That said, overseas medical care can be a reasonable alternative for price sensitive patients in need of relatively common, elective medical procedures. PMID: 21161425 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Liver regeneration, stem cells and beyond. World J Gastrointest Surg. 2009 Nov 30;1(1):6-7 Authors: Ribeiro MA Studies of the liver regenerative process have gained prominence in the last few years, especially with the interest in stem cell therapy. The regenerative capacity of the liver, its mechanisms and the role of stem cells will be discussed in this editorial as well as the role of artificial tissues and organs aiming to produce a new liver based on the current literature. PMID: 21160787 [PubMed - in process] | | | | | | | | | |  | |  | |  |
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