Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dyst... more Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dystrophin in muscle. Affected boys suffer from incurable progressive muscle weakness, leading to premature death. Stem cell transplantation may be curative, but is hampered by the need for systemic delivery and immune rejection. To address these barriers to stem cell therapy in DMD, we investigated a fetal-to-fetal transplantation strategy. We investigated intramuscular, intravascular, and intraperitoneal delivery of human fetal mesenchymal stem cells (hfMSCs) into embryonic day (E) 14–16 MF1 mice to determine the most appropriate route for systemic delivery. Intramuscular injections resulted in local engraftment, whereas both intraperitoneal and intravascular delivery led to systemic spread. However, intravascular delivery led to unexpected demise of transplanted mice. Transplantation of hfMSCs into E14–16 mdx mice resulted in widespread long-term engraftment (19 weeks) in multiple organs, with a predilection for muscle compared with nonmuscle tissues (0.71% vs. 0.15%, p < .01), and evidence of myogenic differentiation of hfMSCs in skeletal and myocardial muscle. This is the first report of intrauterine transplantation of ontologically relevant hfMSCs into fully immunocompetent dystrophic fetal mice, with systemic spread across endothelial barriers leading to widespread long-term engraftment in multiple organ compartments. Although the low-level of chimerism achieved is not curative for DMD, this approach may be useful in other severe mesenchymal or enzyme deficiency syndromes, where low-level protein expression may ameliorate disease pathology.Disclosure of potential conflicts of interest is found at the end of this article.
... Gunther Brunklausa, Jerry CC Chana, Hellmut Eckert*a, Sara Reiserb, Tom Nilgesb and Arno Pfit... more ... Gunther Brunklausa, Jerry CC Chana, Hellmut Eckert*a, Sara Reiserb, Tom Nilgesb and Arno Pfitzner*b. a Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany. ...
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Jan 10, 2015
Several acute monogenic diseases affect multiple body systems, causing death in childhood. The de... more Several acute monogenic diseases affect multiple body systems, causing death in childhood. The development of novel therapies for such conditions is challenging. However, improvements in gene delivery technology mean that gene therapy has the potential to treat such disorders. We evaluated the ability of the AAV9 vector to mediate systemic gene delivery after intravenous administration to perinatal mice and late-gestation nonhuman primates (NHPs). Titer-matched single-stranded (ss) and self-complementary (sc) AAV9 carrying the green fluorescent protein (GFP) reporter gene were intravenously administered to fetal and neonatal mice, with noninjected age-matched mice used as the control. Extensive GFP expression was observed in organs throughout the body, with the epithelial and muscle cells being particularly well transduced. ssAAV9 carrying the WPRE sequence mediated significantly more gene expression than its sc counterpart, which lacked the woodchuck hepatitis virus posttranscripti...
Diamine-functionalized mesoporous SBA-15 materials have been synthesized by co-condensation of te... more Diamine-functionalized mesoporous SBA-15 materials have been synthesized by co-condensation of tetraethylorthosilicate (TEOS) with [3-(2-aminoethyl aminopropyl)]trimethoxysilane (ATMS) using amphiphilic block copolymer P123 as pore-directing agent under the aid of inorganic salt NaCl and with prehydrolysis of TEOS prior to the addition of organosiloxane. The functionalized materials have hexagonal mesostructure ordering, narrow pore-size distribution with diameter around 60Å, and high loadings of
Human endothelial basement membrane (BM) plays a pivotal role in vascular development and homeost... more Human endothelial basement membrane (BM) plays a pivotal role in vascular development and homeostasis. Here, a bio-responsive film with dual-microstructured geometries was engineered to mimic the structural roles of the endothelial BM in developing vessels, for vascular tissue engineering (TE) application. Flexible poly(ε-caprolactone) (PCL) thin film was fabricated with microscale anisotropic ridges/grooves and through-holes using a combination of uniaxial thermal stretching and direct laser perforation, respectively. Through optimizing the inter-hole distance, human mesenchymal stem cells (MSCs) cultured on the PCL film's ridges/grooves obtained an intact cell alignment efficiency. With prolonged culturing for 8 days, these cells formed aligned cell multilayers as found in native tunica media. By co-culturing human umbilical vein endothelial cells (HUVECs) on the opposite side of the film, HUVECs were observed to build up transmural interdigitation cell-cell contact with MSCs ...
Human amniotic epithelial cells (hAECs) have been touted as an ideal stem cell candidate, being e... more Human amniotic epithelial cells (hAECs) have been touted as an ideal stem cell candidate, being ethically neutral, immunologically naïve, plentiful in origin and retaining plasticity in its fetal stage. We hypothesized that by applying natural physiological signals of the developing liver, hAECs can be coaxed into becoming functional immunopermissive hepatocyte-like cells. These cells would have tremendous potential for allogenic cellular transplantation in the treatment of chronic liver insufficiency. hAECs were obtained from term placentas and subjected to hepatic trans-differentiation. Hepatic differentiated cells were analyzed with immunophenotyping, electron microscopy, RT-PCR as well as characterized for hepatic metabolic function. In vivo efficacy was tested using intrasplenic transplantation into NSG mice with thioacetamide-induced chronic liver failure and analyzed for engraftment and improvement in liver indices. With hepatic differentiation, hAECs assumed a hepatocytic polygonal morphology with up regulation of transcription factors responsible for liver specification. These hepatic-differentiated hAECs (HD-AEC) demonstrated bile canaliculi formation, secreted albumin, eliminated indo-cyanine green, uptook low-density lipoprotein, and demonstrated inducible CYP3A4 and CYP2C9 enzymatic activities. Transplantation of hepatic-differentiated hAECs (HD-AEC) and de novo hAECs in mice model of cirrhosis showed successful in vivo engraftment and differentiation into functional hepatocytes positive for human specific albumin. HD-AEC cells that had undergone hepatic differentiation showed the greatest improvement in albumin function while preserving HLA-G expression post differentiation. hAECs were able to differentiate into functional hepatocyte-like cells both in vivo and in vitro. They showed therapeutic efficacy after transplantation in mice model of cirrhosis, offering an exciting source of cells for generation of functionally useful hepatocytes.
We aimed to develop a rapid quantitative-fluorescence polymerase chain reaction (QF-PCR) to detec... more We aimed to develop a rapid quantitative-fluorescence polymerase chain reaction (QF-PCR) to detect common foetal aneuploidies in the Singapore population within 48 hours of sample collection in order to alleviate parental anxiety. DNA from 1,000 foetal samples (978 amniotic fluids, 14 chorion villi and eight foetal blood samples) was analysed using a QF-PCR of 19 microsatellite markers located on chromosomes 13, 18, 21, X and Y. A total of 523 samples were archived before the QF-PCR analysis (archived), while QF-PCR was performed and the results obtained within 48 hours of sample collection in the remaining 477 samples (live). The results were confirmed with their respective karyotypes. In total, 47 autosomal trisomies (T) were found: 30 among the archived (three T13, 12 T18, 15 T21) and 17 among the live (four T18, 13 T21) samples. The QF-PCR results were verified with their respective karyotypes. We achieved 100 percent sensitivity (lower 95 percent confidence interval [CI], 92.8 ...
... in NOD/SCID mice. Exp Hematol 31(10):881–889 Kennea NL, Stratou C, Naparus A, Fisk NM, Mehmet... more ... in NOD/SCID mice. Exp Hematol 31(10):881–889 Kennea NL, Stratou C, Naparus A, Fisk NM, Mehmet H (2005) Functional intrinsic and extrinsic apoptotic pathways in human fetal mesenchymal stem cells. Cell Death Differ ...
American journal of nuclear medicine and molecular imaging, 2013
Stem-cell-based therapies hold promise and potential to address many unmet clinical needs. Cell t... more Stem-cell-based therapies hold promise and potential to address many unmet clinical needs. Cell tracking with modern imaging modalities offers insight into the underlying biological process of the stem-cell-based therapies, with the goal to reveal cell survival, migration, homing, engraftment, differentiation, and functions. Adaptability, sensitivity, resolution, and non-invasiveness have contributed to the longstanding use of optical imaging for stem cell tracking and analysis. To identify transplanted stem cells from the host tissue, optically active probes are usually used to label stem cells before the administration. In comparison to the traditional fluorescent probes like fluorescent proteins and dyes, nanoparticle-based probes are advantageous in terms of the photo-stabilities and minimal changes to the cell phenotype. The main focus here is to overview the recent development of optically active nanoparticles for stem cells tracking. The related optical imaging modalities inc...
Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dyst... more Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dystrophin in muscle. Affected boys suffer from incurable progressive muscle weakness, leading to premature death. Stem cell transplantation may be curative, but is hampered by the need for systemic delivery and immune rejection. To address these barriers to stem cell therapy in DMD, we investigated a fetal-to-fetal transplantation strategy. We investigated intramuscular, intravascular, and intraperitoneal delivery of human fetal mesenchymal stem cells (hfMSCs) into embryonic day (E) 14 -16 MF1 mice to determine the most appropriate route for systemic delivery. Intramuscular injections resulted in local engraftment, whereas both intraperitoneal and intravascular delivery led to systemic spread. However, intravascular delivery led to unexpected demise of trans-planted mice. Transplantation of hfMSCs into E14 -16 mdx mice resulted in widespread long-term engraftment (19 weeks) in multiple organs, with a predilection for muscle compared with nonmuscle tissues (0.71% vs. 0.15%, p < .01), and evidence of myogenic differentiation of hfMSCs in skeletal and myocardial muscle. This is the first report of intrauterine transplantation of ontologically relevant hfMSCs into fully immunocompetent dystrophic fetal mice, with systemic spread across endothelial barriers leading to widespread long-term engraftment in multiple organ compartments. Although the low-level of chimerism achieved is not curative for DMD, this approach may be useful in other severe mesenchymal or enzyme deficiency syndromes, where low-level protein expression may ameliorate disease pathology. STEM CELLS 2007;25:875-884
Tissue-engineered bone grafts (TEBG) require highly osteogenic cell sources for use in fracture r... more Tissue-engineered bone grafts (TEBG) require highly osteogenic cell sources for use in fracture repair applications. Compared to other sources of mesenchymal stem cells (MSC), human fetal MSC (hfMSC) have recently been shown to be more proliferative and osteogenic. We studied the functional performance of hfMSC-mediated TEBG in 7 mm rat femoral critical-sized bone defects (CSD). Dynamicallycultured and osteogenically-primed hfMSC seeded onto macroporous poly-3-caprolactone tri-calcium phosphate scaffolds were transplanted into CSDs. After 12 weeks, hfMSC-mediated TEBG induced 2.1Â more new bone formation (43.3 AE 10.5 vs. 21.0 AE 7.4 mm 3 , p < 0.05), with greater compact and woven bone, and a 9.8Â increase in stiffness (3.9 AE 1.7 vs. 0.4 AE 0.3 mNm/degree, p < 0.05) compared to acellular scaffolds, such that only animals transplanted with TEBG underwent full fracture repair of the CSD. Although hfMSC survived for <4 weeks, by 4 weeks they were associated with a 3.9Â larger vasculature network in the defect area (35.2 AE 11.1 vs. 6.5 AE 3.6 mm 3 p < 0.05), suggesting an important role for hfMSC in the promotion of neo-vasculogenesis. We speculate that hfMSC-mediated healing of the CSD by stimulating neo-vascularization through as yet undetermined mechanisms. This proof-of-principle study demonstrates the utility of primitive MSC for bone regeneration, and may be of relevance to vascularization in other areas of regenerative medicine.
Stem cell transplantation for regenerative medicine has made significant progress in various inju... more Stem cell transplantation for regenerative medicine has made significant progress in various injury models, with the development of modalities to track stem cell fate and migration post-transplantation being currently pursued rigorously. Magnetic resonance imaging (MRI) allows serial high-resolution in vivo detection of transplanted stem cells labeled with iron oxide particles, but has been hampered by low labeling efficiencies. Here, we describe the use of microgel iron oxide (MGIO) particles of diameters spanning 100-750 nm for labeling human fetal mesenchymal stem cells (hfMSCs) for MRI tracking. We found that MGIO particle uptake by hfMSCs was size dependent, with 600-nm MGIO (M600) particles demonstrating threeto sixfold higher iron loading than the clinical particle ferucarbotran (33-263 versus 9.6-42.0 pg iron/hfMSC; p < .001). Cell labeling with either M600 particles or ferucar-botran did not affect either cellular proliferation or trilineage differentiation into osteoblasts, adipocytes, and chondrocytes, despite differences in gene expression on a genome-wide microarray analysis. Cell tracking in a rat photothrombotic stroke model using a clinical 1.5-T MRI scanner demonstrated the migration of labeled hfMSCs from the contralateral cortex to the stroke injury, with M600 particles achieving a five-to sevenfold higher sensitivity for MRI detection than ferucarbotran (p < .05). However, model-related cellular necrosis and acute inflammation limited the survival of hfMSCs beyond 5-12 days. The use of M600 particles allowed high detection sensitivity with low cellular toxicity to be achieved through a simple incubation protocol, and may thus be useful for cellular tracking using standard clinical MRI scanners.
Annals of the Academy of Medicine, Singapore, 2014
Superovulation-intrauterine insemination (SO-IUI) is the most common assisted reproductive techni... more Superovulation-intrauterine insemination (SO-IUI) is the most common assisted reproductive technique (ART) in the world, with good evidence of efficacy and cost-effectiveness. However, parameters affecting its success have not been consistently reported. So in this study, we aim at determining the parameters influencing the success rate of SO-IUI. We conducted a retrospective cohort study of 797 SO-IUI cycles from 606 patients, performed between 2007 and 2009 in a single centre. These women received clomiphene citrate (CC), recombinant FSH (rFSH) or both. There were 127 clinical pregnancies with a pregnancy rate (PR) of 15.9% (127/797) per treatment cycle. Factors associated with higher PR included maternal age <38 (P = 0.02), subfertility diagnoses of ovulatory disorders, unexplained infertility, sexual dysfunction and unilateral tubal obstruction (P = 0.02), an endometrial thickness ≥8 mm (P = 0.03), total number motile spermatozoa (TNMS) of ≥1 million (P = 0.03), and spermatoz...
... Abstract. Myogenic differentiation of galectin-1 pretreated human fetal mesenchymal stem cell... more ... Abstract. Myogenic differentiation of galectin-1 pretreated human fetal mesenchymal stem cells after intra-arterial injection into dystrophic mice / J. Chan, M. Gavina, M. Belicchi, Y. Torrente, JE Morgan, NM Fisk. - In: Atti del Congresso ...
Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dyst... more Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dystrophin in muscle. Affected boys suffer from incurable progressive muscle weakness, leading to premature death. Stem cell transplantation may be curative, but is hampered by the need for systemic delivery and immune rejection. To address these barriers to stem cell therapy in DMD, we investigated a fetal-to-fetal transplantation strategy. We investigated intramuscular, intravascular, and intraperitoneal delivery of human fetal mesenchymal stem cells (hfMSCs) into embryonic day (E) 14–16 MF1 mice to determine the most appropriate route for systemic delivery. Intramuscular injections resulted in local engraftment, whereas both intraperitoneal and intravascular delivery led to systemic spread. However, intravascular delivery led to unexpected demise of transplanted mice. Transplantation of hfMSCs into E14–16 mdx mice resulted in widespread long-term engraftment (19 weeks) in multiple organs, with a predilection for muscle compared with nonmuscle tissues (0.71% vs. 0.15%, p < .01), and evidence of myogenic differentiation of hfMSCs in skeletal and myocardial muscle. This is the first report of intrauterine transplantation of ontologically relevant hfMSCs into fully immunocompetent dystrophic fetal mice, with systemic spread across endothelial barriers leading to widespread long-term engraftment in multiple organ compartments. Although the low-level of chimerism achieved is not curative for DMD, this approach may be useful in other severe mesenchymal or enzyme deficiency syndromes, where low-level protein expression may ameliorate disease pathology.Disclosure of potential conflicts of interest is found at the end of this article.
... Gunther Brunklausa, Jerry CC Chana, Hellmut Eckert*a, Sara Reiserb, Tom Nilgesb and Arno Pfit... more ... Gunther Brunklausa, Jerry CC Chana, Hellmut Eckert*a, Sara Reiserb, Tom Nilgesb and Arno Pfitzner*b. a Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany. ...
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Jan 10, 2015
Several acute monogenic diseases affect multiple body systems, causing death in childhood. The de... more Several acute monogenic diseases affect multiple body systems, causing death in childhood. The development of novel therapies for such conditions is challenging. However, improvements in gene delivery technology mean that gene therapy has the potential to treat such disorders. We evaluated the ability of the AAV9 vector to mediate systemic gene delivery after intravenous administration to perinatal mice and late-gestation nonhuman primates (NHPs). Titer-matched single-stranded (ss) and self-complementary (sc) AAV9 carrying the green fluorescent protein (GFP) reporter gene were intravenously administered to fetal and neonatal mice, with noninjected age-matched mice used as the control. Extensive GFP expression was observed in organs throughout the body, with the epithelial and muscle cells being particularly well transduced. ssAAV9 carrying the WPRE sequence mediated significantly more gene expression than its sc counterpart, which lacked the woodchuck hepatitis virus posttranscripti...
Diamine-functionalized mesoporous SBA-15 materials have been synthesized by co-condensation of te... more Diamine-functionalized mesoporous SBA-15 materials have been synthesized by co-condensation of tetraethylorthosilicate (TEOS) with [3-(2-aminoethyl aminopropyl)]trimethoxysilane (ATMS) using amphiphilic block copolymer P123 as pore-directing agent under the aid of inorganic salt NaCl and with prehydrolysis of TEOS prior to the addition of organosiloxane. The functionalized materials have hexagonal mesostructure ordering, narrow pore-size distribution with diameter around 60Å, and high loadings of
Human endothelial basement membrane (BM) plays a pivotal role in vascular development and homeost... more Human endothelial basement membrane (BM) plays a pivotal role in vascular development and homeostasis. Here, a bio-responsive film with dual-microstructured geometries was engineered to mimic the structural roles of the endothelial BM in developing vessels, for vascular tissue engineering (TE) application. Flexible poly(ε-caprolactone) (PCL) thin film was fabricated with microscale anisotropic ridges/grooves and through-holes using a combination of uniaxial thermal stretching and direct laser perforation, respectively. Through optimizing the inter-hole distance, human mesenchymal stem cells (MSCs) cultured on the PCL film's ridges/grooves obtained an intact cell alignment efficiency. With prolonged culturing for 8 days, these cells formed aligned cell multilayers as found in native tunica media. By co-culturing human umbilical vein endothelial cells (HUVECs) on the opposite side of the film, HUVECs were observed to build up transmural interdigitation cell-cell contact with MSCs ...
Human amniotic epithelial cells (hAECs) have been touted as an ideal stem cell candidate, being e... more Human amniotic epithelial cells (hAECs) have been touted as an ideal stem cell candidate, being ethically neutral, immunologically naïve, plentiful in origin and retaining plasticity in its fetal stage. We hypothesized that by applying natural physiological signals of the developing liver, hAECs can be coaxed into becoming functional immunopermissive hepatocyte-like cells. These cells would have tremendous potential for allogenic cellular transplantation in the treatment of chronic liver insufficiency. hAECs were obtained from term placentas and subjected to hepatic trans-differentiation. Hepatic differentiated cells were analyzed with immunophenotyping, electron microscopy, RT-PCR as well as characterized for hepatic metabolic function. In vivo efficacy was tested using intrasplenic transplantation into NSG mice with thioacetamide-induced chronic liver failure and analyzed for engraftment and improvement in liver indices. With hepatic differentiation, hAECs assumed a hepatocytic polygonal morphology with up regulation of transcription factors responsible for liver specification. These hepatic-differentiated hAECs (HD-AEC) demonstrated bile canaliculi formation, secreted albumin, eliminated indo-cyanine green, uptook low-density lipoprotein, and demonstrated inducible CYP3A4 and CYP2C9 enzymatic activities. Transplantation of hepatic-differentiated hAECs (HD-AEC) and de novo hAECs in mice model of cirrhosis showed successful in vivo engraftment and differentiation into functional hepatocytes positive for human specific albumin. HD-AEC cells that had undergone hepatic differentiation showed the greatest improvement in albumin function while preserving HLA-G expression post differentiation. hAECs were able to differentiate into functional hepatocyte-like cells both in vivo and in vitro. They showed therapeutic efficacy after transplantation in mice model of cirrhosis, offering an exciting source of cells for generation of functionally useful hepatocytes.
We aimed to develop a rapid quantitative-fluorescence polymerase chain reaction (QF-PCR) to detec... more We aimed to develop a rapid quantitative-fluorescence polymerase chain reaction (QF-PCR) to detect common foetal aneuploidies in the Singapore population within 48 hours of sample collection in order to alleviate parental anxiety. DNA from 1,000 foetal samples (978 amniotic fluids, 14 chorion villi and eight foetal blood samples) was analysed using a QF-PCR of 19 microsatellite markers located on chromosomes 13, 18, 21, X and Y. A total of 523 samples were archived before the QF-PCR analysis (archived), while QF-PCR was performed and the results obtained within 48 hours of sample collection in the remaining 477 samples (live). The results were confirmed with their respective karyotypes. In total, 47 autosomal trisomies (T) were found: 30 among the archived (three T13, 12 T18, 15 T21) and 17 among the live (four T18, 13 T21) samples. The QF-PCR results were verified with their respective karyotypes. We achieved 100 percent sensitivity (lower 95 percent confidence interval [CI], 92.8 ...
... in NOD/SCID mice. Exp Hematol 31(10):881–889 Kennea NL, Stratou C, Naparus A, Fisk NM, Mehmet... more ... in NOD/SCID mice. Exp Hematol 31(10):881–889 Kennea NL, Stratou C, Naparus A, Fisk NM, Mehmet H (2005) Functional intrinsic and extrinsic apoptotic pathways in human fetal mesenchymal stem cells. Cell Death Differ ...
American journal of nuclear medicine and molecular imaging, 2013
Stem-cell-based therapies hold promise and potential to address many unmet clinical needs. Cell t... more Stem-cell-based therapies hold promise and potential to address many unmet clinical needs. Cell tracking with modern imaging modalities offers insight into the underlying biological process of the stem-cell-based therapies, with the goal to reveal cell survival, migration, homing, engraftment, differentiation, and functions. Adaptability, sensitivity, resolution, and non-invasiveness have contributed to the longstanding use of optical imaging for stem cell tracking and analysis. To identify transplanted stem cells from the host tissue, optically active probes are usually used to label stem cells before the administration. In comparison to the traditional fluorescent probes like fluorescent proteins and dyes, nanoparticle-based probes are advantageous in terms of the photo-stabilities and minimal changes to the cell phenotype. The main focus here is to overview the recent development of optically active nanoparticles for stem cells tracking. The related optical imaging modalities inc...
Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dyst... more Duchenne muscular dystrophy (DMD) is a common X-linked disease resulting from the absence of dystrophin in muscle. Affected boys suffer from incurable progressive muscle weakness, leading to premature death. Stem cell transplantation may be curative, but is hampered by the need for systemic delivery and immune rejection. To address these barriers to stem cell therapy in DMD, we investigated a fetal-to-fetal transplantation strategy. We investigated intramuscular, intravascular, and intraperitoneal delivery of human fetal mesenchymal stem cells (hfMSCs) into embryonic day (E) 14 -16 MF1 mice to determine the most appropriate route for systemic delivery. Intramuscular injections resulted in local engraftment, whereas both intraperitoneal and intravascular delivery led to systemic spread. However, intravascular delivery led to unexpected demise of trans-planted mice. Transplantation of hfMSCs into E14 -16 mdx mice resulted in widespread long-term engraftment (19 weeks) in multiple organs, with a predilection for muscle compared with nonmuscle tissues (0.71% vs. 0.15%, p < .01), and evidence of myogenic differentiation of hfMSCs in skeletal and myocardial muscle. This is the first report of intrauterine transplantation of ontologically relevant hfMSCs into fully immunocompetent dystrophic fetal mice, with systemic spread across endothelial barriers leading to widespread long-term engraftment in multiple organ compartments. Although the low-level of chimerism achieved is not curative for DMD, this approach may be useful in other severe mesenchymal or enzyme deficiency syndromes, where low-level protein expression may ameliorate disease pathology. STEM CELLS 2007;25:875-884
Tissue-engineered bone grafts (TEBG) require highly osteogenic cell sources for use in fracture r... more Tissue-engineered bone grafts (TEBG) require highly osteogenic cell sources for use in fracture repair applications. Compared to other sources of mesenchymal stem cells (MSC), human fetal MSC (hfMSC) have recently been shown to be more proliferative and osteogenic. We studied the functional performance of hfMSC-mediated TEBG in 7 mm rat femoral critical-sized bone defects (CSD). Dynamicallycultured and osteogenically-primed hfMSC seeded onto macroporous poly-3-caprolactone tri-calcium phosphate scaffolds were transplanted into CSDs. After 12 weeks, hfMSC-mediated TEBG induced 2.1Â more new bone formation (43.3 AE 10.5 vs. 21.0 AE 7.4 mm 3 , p < 0.05), with greater compact and woven bone, and a 9.8Â increase in stiffness (3.9 AE 1.7 vs. 0.4 AE 0.3 mNm/degree, p < 0.05) compared to acellular scaffolds, such that only animals transplanted with TEBG underwent full fracture repair of the CSD. Although hfMSC survived for <4 weeks, by 4 weeks they were associated with a 3.9Â larger vasculature network in the defect area (35.2 AE 11.1 vs. 6.5 AE 3.6 mm 3 p < 0.05), suggesting an important role for hfMSC in the promotion of neo-vasculogenesis. We speculate that hfMSC-mediated healing of the CSD by stimulating neo-vascularization through as yet undetermined mechanisms. This proof-of-principle study demonstrates the utility of primitive MSC for bone regeneration, and may be of relevance to vascularization in other areas of regenerative medicine.
Stem cell transplantation for regenerative medicine has made significant progress in various inju... more Stem cell transplantation for regenerative medicine has made significant progress in various injury models, with the development of modalities to track stem cell fate and migration post-transplantation being currently pursued rigorously. Magnetic resonance imaging (MRI) allows serial high-resolution in vivo detection of transplanted stem cells labeled with iron oxide particles, but has been hampered by low labeling efficiencies. Here, we describe the use of microgel iron oxide (MGIO) particles of diameters spanning 100-750 nm for labeling human fetal mesenchymal stem cells (hfMSCs) for MRI tracking. We found that MGIO particle uptake by hfMSCs was size dependent, with 600-nm MGIO (M600) particles demonstrating threeto sixfold higher iron loading than the clinical particle ferucarbotran (33-263 versus 9.6-42.0 pg iron/hfMSC; p < .001). Cell labeling with either M600 particles or ferucar-botran did not affect either cellular proliferation or trilineage differentiation into osteoblasts, adipocytes, and chondrocytes, despite differences in gene expression on a genome-wide microarray analysis. Cell tracking in a rat photothrombotic stroke model using a clinical 1.5-T MRI scanner demonstrated the migration of labeled hfMSCs from the contralateral cortex to the stroke injury, with M600 particles achieving a five-to sevenfold higher sensitivity for MRI detection than ferucarbotran (p < .05). However, model-related cellular necrosis and acute inflammation limited the survival of hfMSCs beyond 5-12 days. The use of M600 particles allowed high detection sensitivity with low cellular toxicity to be achieved through a simple incubation protocol, and may thus be useful for cellular tracking using standard clinical MRI scanners.
Annals of the Academy of Medicine, Singapore, 2014
Superovulation-intrauterine insemination (SO-IUI) is the most common assisted reproductive techni... more Superovulation-intrauterine insemination (SO-IUI) is the most common assisted reproductive technique (ART) in the world, with good evidence of efficacy and cost-effectiveness. However, parameters affecting its success have not been consistently reported. So in this study, we aim at determining the parameters influencing the success rate of SO-IUI. We conducted a retrospective cohort study of 797 SO-IUI cycles from 606 patients, performed between 2007 and 2009 in a single centre. These women received clomiphene citrate (CC), recombinant FSH (rFSH) or both. There were 127 clinical pregnancies with a pregnancy rate (PR) of 15.9% (127/797) per treatment cycle. Factors associated with higher PR included maternal age <38 (P = 0.02), subfertility diagnoses of ovulatory disorders, unexplained infertility, sexual dysfunction and unilateral tubal obstruction (P = 0.02), an endometrial thickness ≥8 mm (P = 0.03), total number motile spermatozoa (TNMS) of ≥1 million (P = 0.03), and spermatoz...
... Abstract. Myogenic differentiation of galectin-1 pretreated human fetal mesenchymal stem cell... more ... Abstract. Myogenic differentiation of galectin-1 pretreated human fetal mesenchymal stem cells after intra-arterial injection into dystrophic mice / J. Chan, M. Gavina, M. Belicchi, Y. Torrente, JE Morgan, NM Fisk. - In: Atti del Congresso ...
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