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| Incident at the Marriott: Stem Cell Agency Bars Public From Meeting
June 18, 2010 at 6:46 PM
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| The California stem cell agency barred two academics from entering one of its conferences earlier this week in San Francisco.
The action appears to violate the spirit and probably the letter of the California State Constitution and state open meeting laws. Under section three of the constitution, approved by 83 percent of voters in 2004, members of the public have a broadly construed right of | | |
| Yamanaka Wins Kyoto Award
June 18, 2010 at 4:29 PM
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| The Japanese stem cell scientist who pioneered reprogramming of adult stem cells has won the prestigious Kyoto Award, a $550,000 prize from the Inamori Foundation for research in advanced technology.
Shinya Yamanaka, who also has a lab at UCSF's Gladstone Institutes and is working with a CIRM-connected firm, is in San Francisco for the International Society of Stem Cell Research's annual | | |
| Six Scientists Appeal Rejection of Grants; Read Their Letters to CIRM
June 18, 2010 at 11:07 AM
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| Six researchers this week are publicly appealing negative decisions on their requests for millions of dollars from the $3 billion California stem cell agency.
The "extraordinary petitions," which are available online, were filed in connection with a $30 million round of stem cell immunology grants that the CIRM board is scheduled to vote on at a meeting in San Diego beginning next Tuesday. | | |
| Induced differentiation of adipose-derived stromal cells into myoblasts.
June 18, 2010 at 6:57 AM
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| | Induced differentiation of adipose-derived stromal cells into myoblasts. J Huazhong Univ Sci Technolog Med Sci. 2010 Jun;30(3):285-90 Authors: Wu G, Zheng X, Jiang Z, Wang J, Song Y This study aimed to induce the differentiation of isolated and purified adipose-derived stromal cells (ADSCs) into myoblasts, which may provide a new strategy for tissue engineering in patients with stress urinary incontinence (SUI). ADSCs, isolated and cultured ex vivo, were identified by flow cytometry and induced to differentiate into myoblasts in the presence of an induction solution consisting of DMEM supplemented with 5-azacytidine (5-aza), 5% FBS, and 5% horse serum. Cellular morphology was observed under an inverted microscope. Ultrastructural changes occurring during the differentiation were observed by transmission electron microscopy and confocal laser scanning microscopy. Cellular immunohistochemical staining was applied to determine the expression of desmin protein in cells with and without induced differentiation. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to detect mRNA and protein expression, respectively, of sarcomeric and desmin smooth muscle proteins. The results showed that ADSCs were mainly of a spindle or polygon shape. Flow cytometry analysis revealed that ADSCs did not express CD34, CD45, and CD106 but high levels of CD44 and CD90, which confirmed that the cultured cells were indeed ADSCs. After induction with a 5-aza-containing solution, morphological changes in ADSCs, including irregular cell size, were observed. Cells gradually changed from long spindles to polygons and star-shaped cells with microvilli on the cell surface. Many organelles were observed and the cytoplasm was found to contain many mitochondria, rough endoplasmic reticulum (rER), and myofilament-like structures. Cell immunohistochemical staining revealed different levels of desmin expression in each phase of the induction process, with the highest expression level found on day 28 of induction. RT-PCR and Western blot results confirmed significantly higher desmin gene expression in induced cells compared with control cells, but no significant difference between the two groups of cells in sarcomeric protein expression. It was concluded that under specific induction setting, ADSCs can be induced to differentiate into myoblasts, providing a potential new option in stem cell transplantation therapy for SUI. PMID: 20556569 [PubMed - in process] | | |
| Lab-on-a-chip devices as an emerging platform for stem cell biology.
June 18, 2010 at 6:32 AM
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| | Lab-on-a-chip devices as an emerging platform for stem cell biology. Lab Chip. 2010 Jun 16; Authors: Gupta K, Kim DH, Ellison D, Smith C, Kundu A, Tuan J, Suh KY, Levchenko A The advent of stem cell based therapies has brought regenerative medicine into an increased focus as a part of the modern medicine practice, with a potential to treat a myriad of intractable diseases in the future. Stem cells reside in a complex microenvironment presenting them with a multitude of potential cues that are chemical, physical, and mechanical in nature. Conventional techniques used for experiments involving stem cells can only poorly mimic the physiological context, and suffer from imprecise spatial and temporal control, low throughput, lack of scalability and reproducibility, and poor representation of the mechanical and physical cell microenvironment. Novel lab-on-a-chip platforms, on the other hand, can much better mimic the complexity of in vivo tissue milieu and provide a greater control of the parameter variation in a high throughput and scalable manner. This capability may be especially important for understanding the biology and cementing the clinical potential of stem cell based therapies. Here we review microfabrication- and microfluidics-based approaches to investigating the complex biology of stem cell responses to changes in the local microenvironment. In particular, we categorize each method based on the types of controlled inputs it can have on stem cells, including soluble biochemical factors, extracellular matrix interactions, homotypic and heterotypic cell-cell signaling, physical cues (e.g. oxygen tension, pH, temperature), and mechanical forces (e.g. shear, topography, rigidity). Finally, we outline the methods to perform large scale observations of stem cell phenotypes and high-throughput screening of cellular responses to a combination of stimuli, and many new emerging technologies that are becoming available specifically for stem cell applications. PMID: 20556297 [PubMed - as supplied by publisher] | | |
| Stem cells.
June 18, 2010 at 6:32 AM
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| | Stem cells. Plast Reconstr Surg. 2010 Jun 15; Authors: Behr B, Hee Ko S, Wong VW, Gurtner GC, Longaker MT Stem cells are self-renewing cells capable of differentiating into multiple cell lines and are classified according to their origin and their ability to differentiate. Enormous potential exists in use of stem cells for regenerative medicine. In order to produce effective stem cell-based treatments for a range of diseases, an improved understanding of stem cell biology and better control over stem-cell fate are necessary. In addition, the barriers to clinical translation such as potential oncologic properties of stem cells need to be addressed. With renewed government support and continued refinement of current stem cell methodologies, the future of stem cell research is exciting and promises to provide novel reconstructive options for patients and surgeons limited by traditional paradigms. PMID: 20555302 [PubMed - as supplied by publisher] | | |
| Dental Pulp Cells for Induced Pluripotent Stem Cell Banking.
June 18, 2010 at 6:32 AM
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| | Dental Pulp Cells for Induced Pluripotent Stem Cell Banking. J Dent Res. 2010 Jun 16; Authors: Tamaoki N, Takahashi K, Tanaka T, Ichisaka T, Aoki H, Takeda-Kawaguchi T, Iida K, Kunisada T, Shibata T, Yamanaka S, Tezuka K Defined sets of transcriptional factors can reprogram human somatic cells to induced pluripotent stem (iPS) cells. However, many types of human cells are not easily accessible to minimally invasive procedures. Here we evaluated dental pulp cells (DPCs) as an optimal source of iPS cells, since they are easily obtained from extracted teeth and can be expanded under simple culture conditions. From all 6 DPC lines tested with the conventional 3 or 4 reprogramming factors, iPS cells were effectively established from 5 DPC lines. Furthermore, determination of the HLA types of 107 DPC lines revealed 2 lines homozygous for all 3 HLA loci and showed that if an iPS bank is established from these initial pools, the bank will cover approximately 20% of the Japanese population with a perfect match. Analysis of these data demonstrates the promising potential of DPC collections as a source of iPS cell banks for use in regenerative medicine. PMID: 20554890 [PubMed - as supplied by publisher] | | |
| Different effects of scopolamine on the retrieval of spatial memory and fear memory.
June 18, 2010 at 6:32 AM
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| | Different effects of scopolamine on the retrieval of spatial memory and fear memory. Behav Brain Res. 2010 May 26; Authors: Huang ZB, Wang H, Rao XR, Zhong GF, Hu WH, Sheng GQ Retrieval of memory is fundamental for our life as individuals. The participation of cholinergic system in memory consolidation process has been extensively studied, but there are few data concerning the function of this system in memory retrieval process. In the current study, we inject non-selective muscarinic antagonist scopolamine peripherally 20minutes before training or testing to see whether cholinergic modulation has effects on the acquisition or retrieval of spatial memory by water maze task and fear memory by inhibitory avoidance task. We find that the cholinergic system is essential for the acquisition of both spatial memory and fear memory. As for the memory retrieval, the cholinergic system has a positive role in the retrieval of spatial memory, because mice injected with scopolamine 20minutes before the testing in the water maze show impaired spatial memory retrieval. Whereas injection of scopolamine 20minutes before the testing in the inhibitory avoidance task doesn't cause memory retrieval deficits. That indicates the cholinergic system isn't essential for the retrieval of fear memory. PMID: 20553767 [PubMed - as supplied by publisher] | | |
| Adhesion Force Studies of Nanofibers and Nanoparticles.
June 18, 2010 at 6:32 AM
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| | Adhesion Force Studies of Nanofibers and Nanoparticles. Langmuir. 2010 Jun 16; Authors: Xing M, Zhong W, Xu X, Thomson D Surface adhesion between nanofibers and nanoparticles has attracted attention for potential biomedical applications, but the measurement has not been reported. Adhesion forces were measured using a polystyrene (PS) nanoparticle attached to an atomic force microscopy (AFM) tip/probe. Electrospun PS nanofibers of different diameters were tapped with the probe to study the effect of fiber diameters on adhesion force. Both AFM experiments and numerical models suggest that the adhesion force increases with increased fiber diameters. Numerical models further demonstrated that local deformation of the fiber surface, including the flattening of surface asperities and the nanofiber wrapping around the particle during contact, may have a significant impact on the adhesion force. The adhesion forces are in the order of 100 nN, much smaller than the adhesion forces of the gecko foot hair, but much larger than that of the receptor-ligand pair, antibody-antigen pair, and single-stranded DNA from a substrate. Adhesion forces of nanofibers with roughness were predicted by numerical analysis. This study is expected to provide approaches and information useful in the design of nanomedicine and scaffold based on nanofibers for tissue engineering and regenerative medicine. PMID: 20552953 [PubMed - as supplied by publisher] | | |
| Recommendations for successful training on methods of delivery of biologics for cardiac regeneration: a report of the International Society for Cardiovascular Translational Research.
June 18, 2010 at 6:32 AM
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| | Recommendations for successful training on methods of delivery of biologics for cardiac regeneration: a report of the International Society for Cardiovascular Translational Research. JACC Cardiovasc Interv. 2010 Mar;3(3):265-75 Authors: Dib N, Menasche P, Bartunek JJ, Zeiher AM, Terzic A, Chronos NA, Henry TD, Peters NS, Fernández-Avilés F, Yacoub M, Sanborn TA, Demaria A, Schatz RA, Taylor DA, Fuchs S, Itescu S, Miller LW, Dinsmore JH, Dangas GD, Popma JJ, Hall JL, Holmes DR, The field of myocardial regeneration (angiogenesis and myogenesis) might prove to play an important role in the future management of cardiovascular disease. Stem cells are currently undergoing testing in Phase I and Phase II clinical trials. Methods of delivery will affect the outcome of such therapies, perhaps significantly. This document provides suggested guidance in 4 methods of delivery: endocardial, intracoronary, coronary sinus, and epicardial. PMID: 20298983 [PubMed - indexed for MEDLINE] | | |
| Stem cell and progenitor cell therapy in peripheral artery disease. A critical appraisal.
June 18, 2010 at 6:32 AM
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| | Stem cell and progenitor cell therapy in peripheral artery disease. A critical appraisal. Thromb Haemost. 2010 Mar 31;103(4):696-709 Authors: Lawall H, Bramlage P, Amann B Atherosclerotic peripheral artery disease (PAD) is a common manifestation of atherosclerosis. The occlusion of large limb arteries leads to ischaemia with claudication which can progress to critical limb ischaemia (CLI) with pain at rest, and to tissue loss. At present, common therapy for CLI is either surgical or endovascular revascularisation aimed at improving blood flow to the affected extremity. However, major amputation and death are still frequent complications. Exploring new strategies for revascularisation of ischaemic limbs is thus of major importance. Bone marrow (BM)-derived stem and progenitor cells have been identified as a potential new therapeutic option to induce therapeutic angiogenesis. Encouraging results of preclinical studies have rapidly led to several small clinical trials, in which BM-derived mononuclear cells were administered to patients with limb ischaemia. Clinical benefits were reported from these trials including improvement of ankle-brachial index (ABI), transcutaneous partial pressure of oxygen (TcPO2), reduction of pain, and decreased need for amputation. Nonetheless, large randomised, placebo-controlled, double-blind studies are necessary and currently ongoing (BONMOT-CLI, JUVENTUS and NCT00498069). Further research relates to the optimal cell type and dosage, the isolation method, the role of colony-stimulating factors, administration route, and the supportive stimulation of cells with reduced functioning due to advanced PAD. Autologous stem cell therapy for ischaemic peripheral disease seems to be a promising new tool for the treatment of severe limb ischaemia. Preliminary evidence has established its safety, feasibility and effectiveness on several important endpoints. Several large endpoints studies are underway to further consolidate this evidence. PMID: 20174766 [PubMed - indexed for MEDLINE] | | |
| Facial reconstruction by biosurgery: cell transplantation versus cell homing.
June 18, 2010 at 6:32 AM
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| | Facial reconstruction by biosurgery: cell transplantation versus cell homing. Tissue Eng Part B Rev. 2010 Apr;16(2):257-62 Authors: Mao JJ, Stosich MS, Moioli EK, Lee CH, Fu SY, Bastian B, Eisig SB, Zemnick C, Ascherman J, Wu J, Rohde C, Ahn J The face distinguishes one human being from another. When the face is disfigured because of trauma, tumor removal, congenital anomalies, or chronic diseases, the patient has a strong desire for functional and esthetic restoration. Current practice of facial reconstruction using autologous grafts, synthetic fillers, and prostheses is frequently below the surgeon's and patient's expectations. Facial reconstruction is yet to take advantage of recent advances in seemingly unrelated fields of stem cell biology, chemical engineering, biomaterials, and tissue engineering. "Biosurgery," a new concept that we propose, will incorporate novel principles and strategies of bioactive cues, biopolymers, and/or cells to restore facial defects. Small facial defects can likely be reconstructed by cell homing and without cell transplantation. A critical advantage of cell homing is that agilely recruited endogenous cells have the potential to harness the host's innate capacity for regeneration, thus accelerating the rate of regulatory and commercialization processes for product development. Large facial defects, however, may not be restorable without cell delivery per our understanding at this time. New breakthrough in biosurgery will likely originate from integrated strategies of cell biology, cytokine biology, chemical engineering, biomaterials, and tissue engineering. Regardless of cell homing or cell delivery approaches, biosurgery not only will minimize surgical trauma and repetitive procedures, but also produce long-lasting results. At the same time, caution must be exercised against the development of products that lack scientific basis or dogmatic combination of cells, biomaterials, and biomolecules. Together, scientifically derived biosurgery will undoubtedly develop into new technologies that offer increasingly natural reconstruction and/or augmentation of the face. PMID: 19891541 [PubMed - indexed for MEDLINE] | | |
| Induced differentiation of adipose-derived stromal cells into myoblasts.
June 18, 2010 at 6:15 AM
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| | Induced differentiation of adipose-derived stromal cells into myoblasts. J Huazhong Univ Sci Technolog Med Sci. 2010 Jun;30(3):285-90 Authors: Wu G, Zheng X, Jiang Z, Wang J, Song Y This study aimed to induce the differentiation of isolated and purified adipose-derived stromal cells (ADSCs) into myoblasts, which may provide a new strategy for tissue engineering in patients with stress urinary incontinence (SUI). ADSCs, isolated and cultured ex vivo, were identified by flow cytometry and induced to differentiate into myoblasts in the presence of an induction solution consisting of DMEM supplemented with 5-azacytidine (5-aza), 5% FBS, and 5% horse serum. Cellular morphology was observed under an inverted microscope. Ultrastructural changes occurring during the differentiation were observed by transmission electron microscopy and confocal laser scanning microscopy. Cellular immunohistochemical staining was applied to determine the expression of desmin protein in cells with and without induced differentiation. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to detect mRNA and protein expression, respectively, of sarcomeric and desmin smooth muscle proteins. The results showed that ADSCs were mainly of a spindle or polygon shape. Flow cytometry analysis revealed that ADSCs did not express CD34, CD45, and CD106 but high levels of CD44 and CD90, which confirmed that the cultured cells were indeed ADSCs. After induction with a 5-aza-containing solution, morphological changes in ADSCs, including irregular cell size, were observed. Cells gradually changed from long spindles to polygons and star-shaped cells with microvilli on the cell surface. Many organelles were observed and the cytoplasm was found to contain many mitochondria, rough endoplasmic reticulum (rER), and myofilament-like structures. Cell immunohistochemical staining revealed different levels of desmin expression in each phase of the induction process, with the highest expression level found on day 28 of induction. RT-PCR and Western blot results confirmed significantly higher desmin gene expression in induced cells compared with control cells, but no significant difference between the two groups of cells in sarcomeric protein expression. It was concluded that under specific induction setting, ADSCs can be induced to differentiate into myoblasts, providing a potential new option in stem cell transplantation therapy for SUI. PMID: 20556569 [PubMed - in process] | | |
| A new technique for seeding chondrocytes onto solvent-preserved human meniscus using the chemokinetic effect of recombinant human bone morphogenetic protein-2.
June 18, 2010 at 6:15 AM
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| | A new technique for seeding chondrocytes onto solvent-preserved human meniscus using the chemokinetic effect of recombinant human bone morphogenetic protein-2. Cell Tissue Bank. 2010 Jun 17; Authors: Minehara H, Urabe K, Naruse K, Mehlhorn AT, Uchida K, Südkamp NP, Itoman M Many investigators are currently studying the use of decellularized tissue allografts from human cadavers as scaffolds onto which patients' cells could be seeded, or as carriers for genetically engineered cells to aid cell transplantation. However, it is difficult to seed cells onto very dense regular connective tissue which has few interstitial spaces. Here, we discuss the development of a chemotactic cell seeding technique using solvent-preserved human meniscus. A chemokinetic response to recombinant human bone morphogenetic protein-2 (rhBMP-2) was observed in a monolayer culture of primary chondrocytes derived from femoral epiphyseal cartilage of 2-day-old rats. The rhBMP-2 significantly increased their migration upto 10 ng/ml in a dose-dependent manner. When tested with solvent-preserved human meniscus as a scaffold, which has few interstitial spaces, rhBMP-2 was able to induce chondrocytes to migrate into the meniscus. After a 3-week incubation, newly-formed cartilaginous extracellular matrix was synthesized by migrated chondrocytes throughout the meniscus, down to a depth of 3 mm. These findings demonstrate that rhBMP-2 may be a natural chemokinetic factor in vivo, which induces migration of proliferative chondrocytes into the narrow interfibrous spaces. Our results suggest a potential application of rhBMP-2 for the designed distribution of chondrocytes into a scaffold to be used for tissue engineering. PMID: 20556521 [PubMed - as supplied by publisher] | | |
| Phenotypic Variations in Chondrocyte Subpopulations and Their Response to In Vitro Culture and External Stimuli.
June 18, 2010 at 6:15 AM
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| | Phenotypic Variations in Chondrocyte Subpopulations and Their Response to In Vitro Culture and External Stimuli. Ann Biomed Eng. 2010 Jun 17; Authors: Coates EE, Fisher JP Articular cartilage defects have limited capacity to self-repair, and cost society up to 60 billion dollars annually in both medical treatments and loss of working days. Recent developments in cartilage tissue engineering have resulted in many new products coming to market or entering clinical trials. However, there is a distinct lack of treatments which aim to recreate the complex zonal organization of articular cartilage. Cartilage tissue withstands repetitive strains throughout an individual's lifetime and provides frictionless movement between joints. The structure and composition of its intricately organized extracellular matrix varies with tissue depth to provide optimal resistance to loading, ensure ease of movement, and integrate with the subchondral bone. Each tissue zone is specially designed to resist the load it experiences, and maximize the tissue properties needed for its location. It is unlikely that a homogenous solution to tissue repair will be able to optimally restore the function of such a heterogeneous tissue. For zonal engineering of articular cartilage to become practical, maintenance of phenotypically stable zonal cell populations must be achieved. The chondrocyte phenotype varies considerably by zone, and it is the activity of these cells that help achieve the structural organization of the tissue. This review provides an examination of literature which has studied variations in cellular phenotype between cartilage zones. By doing so, we have identified critical differences between cell populations and highlighted areas of research which show potential in the field. Current research has made the morphological and metabolic variations between these cell populations clear, but an ideal way of maintaining these differences in vitro culture is yet to be established. Combinations of delivered growth factors, mechanical loading, and layered three-dimensional culture systems all show potential for achieving this goal. Furthermore, differentiation of progenitor cell populations into chondrocyte subpopulations may also hold promise for achieving large numbers of zonal chondrocytes. Success of the field lies in establishing methods of retaining phenotypically stable cell populations for in vitro culture. PMID: 20556515 [PubMed - as supplied by publisher] | | |
| Effects of enamel matrix derivative on bioactive glass in rat calvarium defects.
June 18, 2010 at 6:15 AM
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| | Effects of enamel matrix derivative on bioactive glass in rat calvarium defects. J Oral Implantol. 2010;36(3):195-204 Authors: Potijanyakul P, Sattayasansakul W, Pongpanich S, Leepong N, Kintarak S Abstract Tissue engineering-based bone grafting has emerged as a viable alternative to biologic and synthetic grafts. The purpose of this study was to evaluate the effect of enamel matrix derivative (EMD; Emdogain gel, Biora AB, Malmö, Sweden) on bioactive glass in enhancing bone formation in rat calvarium defects. Twenty rats were used in the study. In all animals, 2 standardized critical-sized calvarial defects (5.0 mm diameter) were created surgically. The animals were randomly allocated into 4 groups of 5 animals each. Group AI: one calvarial defect was filled with bioactive glass plus EMD, while the contralateral defect was filled with bioactive glass alone. The healing period was 2 weeks. Groups AII and AIII: the animals were treated in the same manner as in group AI, but the healing periods were 4 and 8 weeks, respectively. Group B: one calvarial defect was filled with EMD only, while the contralateral defect was empty (CSD). The healing period was 8 weeks. New bone formation was evaluated by radiomorphometry and histomorphometry. Results of radiomorphometry showed no significant difference in the mean optical density between bioactive glass with EMD and bioactive glass alone; no defect completely regenerated with bone. The histologic analysis revealed that defects filled with bioactive glass plus EMD in all groups contained slightly more percentage of new bone than those filled with bioactive glass alone; however, the difference was not statistically significant. The highest percentage of new bone formation was present at 8 weeks in the bioactive glass plus EMD group. Bioactive glass particles, used with or without EMD, maintained the volume and contour of the area grafted in CSD. However, they did not lead to a significant difference in bone formation when compared with CSD 8 weeks postoperatively. PMID: 20553173 [PubMed - in process] | | |
| Adhesion Force Studies of Nanofibers and Nanoparticles.
June 18, 2010 at 6:15 AM
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| | Adhesion Force Studies of Nanofibers and Nanoparticles. Langmuir. 2010 Jun 16; Authors: Xing M, Zhong W, Xu X, Thomson D Surface adhesion between nanofibers and nanoparticles has attracted attention for potential biomedical applications, but the measurement has not been reported. Adhesion forces were measured using a polystyrene (PS) nanoparticle attached to an atomic force microscopy (AFM) tip/probe. Electrospun PS nanofibers of different diameters were tapped with the probe to study the effect of fiber diameters on adhesion force. Both AFM experiments and numerical models suggest that the adhesion force increases with increased fiber diameters. Numerical models further demonstrated that local deformation of the fiber surface, including the flattening of surface asperities and the nanofiber wrapping around the particle during contact, may have a significant impact on the adhesion force. The adhesion forces are in the order of 100 nN, much smaller than the adhesion forces of the gecko foot hair, but much larger than that of the receptor-ligand pair, antibody-antigen pair, and single-stranded DNA from a substrate. Adhesion forces of nanofibers with roughness were predicted by numerical analysis. This study is expected to provide approaches and information useful in the design of nanomedicine and scaffold based on nanofibers for tissue engineering and regenerative medicine. PMID: 20552953 [PubMed - as supplied by publisher] | | | | 
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