Publications by authors named "Peter K Law"

Remote and robotically actuated catheters are the stepping-stones toward autonomous catheters, where complex intravascular procedures may be performed with minimal intervention from a physician. This article proposes a concept for the positional, feedforward control of a robotically actuated cell injection catheter used for the injection of myogenic or undifferentiated stem cells into the myocardial infarct boundary zones of the left ventricle. The prototype for the catheter system was built upon a needle-based catheter with a single degree of deflection, a 3-D printed handle combined with actuators, and the Arduino microcontroller platform.

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This article discusses existing catheter systems and proposes a conceptual design and procedure for an autonomous cell injection catheter for the purpose of transferring committed myogenic or undifferentiated stem cells into the infarct boundary zones of the left ventricle. Operation of existing catheters used for cell delivery is far from optimal. Commercial injection catheters available are handheld devices operated manually by means of tip deflection and torque capabilities.

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Aim: The study aims to investigate the gene expression profiling of insulin signaling pathway and mitochondrial biogenesis and function in the skeletal muscle of KK mice.

Methods: KK mice were divided into the following groups: KK control group, basal medium (M199) only; KK fibroblast group, with human fibroblast transplantation; KK myoblast group, with human skeletal myoblast transplantation. C57BL mice received hSkM transplantation as a normal control.

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The study aims to use cholesterol (Chol) + DOTAP liposome (CD liposome) based human vascular endothelial growth factor-165 (VEGF(165)) gene transfer into skeletal myoblasts (SkMs) for treatment of acute hind limb ischaemia in a rabbit model. The feasibility and efficacy of CD liposome mediated gene transfer with rabbit SkMs were characterized using plasmid carrying enhanced green fluorescent protein (pEGFP) and assessed by flow cytometry. After optimization, SkMs were transfected with CD lipoplexes carrying plasmid-VEGF(165) (CD-pVEGF(165)) and transplanted into rabbit ischaemic limb.

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We aim to investigate the feasibility and efficacy of cholesterol (Chol)+DOTAP liposome (CD liposome) based human vascular endothelial growth factor-165 (hVEGF(165)) gene transfer into human skeletal myoblasts (hSkM) for cardiac repair. The feasibility and efficacy of CD liposome for gene transfer with hSkM was characterized using plasmid carrying enhanced green fluorescent protein (pEGFP). Based on the optimized transfection procedure, hSkM were transfected with CD lipoplexes carrying plasmid-hVEGF(165) (CD-phVEGF(165)).

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Low-level transgene efficiency is one of the main obstacles in ex vivo nonviral vector-mediated gene transfer into primary human skeletal myoblasts (hSkMs). We optimized the cholesterol:N-[1-(2, 3-dioleoyloxy)propyl]-N, N, N-trimethylammonium methylsulfate liposome (CD liposome) and 22-kDa polyethylenimine (PEI22)- and 25-kDa polyethylenimine (PEI25)-mediated transfection of primary hSkMs for angiogenic gene delivery. We found that transfection efficiency and cell viability of three nonviral vectors were cell passage dependent: early cell passages of hSkMs had higher transfection efficiencies with poor cell viabilities, whereas later cell passages of hSkMs had lower transfection efficiencies with better cell viabilities.

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Objective: We sought to investigate immune cell kinetics in relation to skeletal myoblast survival and heart function improvement after nonautologous skeletal myoblast transplantation in a rat model of myocardial infarction.

Methods: One week after myocardial infarction, 208 Wistar rats were grouped into group 1 (n = 24, receiving 150 muL of medium only), group 2 (n = 24, receiving 150 muL of medium and cyclosporine [INN: ciclosporin]), group 3 (n = 40, human skeletal myoblast transplantation), group 4 (n = 40, human skeletal myoblast transplantation with cyclosporine treatment), group 5 (n = 40, rat skeletal myoblast transplantation), and group 6 (n = 40, rat skeletal myoblast transplantation with cyclosporine treatment). The hearts were harvested at 10 minutes and 1, 4, 7, and 28 days after cell transplantation.

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Background: We investigated the feasibility and efficacy of polyethylenimine (PEI) based human vascular endothelial growth factor-165 (hVEGF165) gene transfer into human skeletal myoblasts (HSM) for cell based delivery to the infarcted myocardium.

Methods And Results: Based on optimized transfection procedure using enhanced green fluorescent protein (pEGFP), HSM were transfected with plasmid-hVEGF165 (phVEGF165) carried by PEI (PEI-phVEGF165) nanoparticles. The transfected HSM were characterized for transfection and expression of hVEGF165 in vitro and transplanted into rat heart model of acute myocardial infarction (AMI): group-1=DMEM injection, group-2= HSM transplantation, group-3= PEI-phVEGF165-transfected HSM (PEI-phVEGF165 myoblast) transplantation.

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Objective: To achieve angiogenic interaction between VEGF(165) and angiopoietin-1 (Ang-1) using a novel adenoviral bicistronic vector (Ad-Bic) encoding the two factors and delivered ex vivo using sex-mismatched human skeletal myoblasts.

Methods And Results: A myocardial infarction model was developed in 29 female pigs; randomised into four groups: DMEM (group-1, n=6); Adenovirus null (Ad-null) vector-myoblast (group-2, n=5); Ad-Ang-1 myoblast (group 3, n=7) and Ad-Bic-myoblast (group-4, n=11). Three weeks later, 5 ml DMEM without myoblasts or containing 3 x 10(8) myoblasts carrying lac-z gene and transduced with Ad-null, Ad-Ang-1 or Ad-Bic were injected intra-myocardially in and around the infarct.

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Cellular cardiomyoplasty using various types of donor cells is now validated by a large number of experimental studies. We report a case of cellular cardiomyoplasty performed on a beating heart using autologous skeletal myoblasts, thus combining the efficacy of both procedures. Approximately 2.

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Background: We hypothesized that combination therapy using human myoblasts and VEGF165 will lead to better prognosis in a failing heart.

Methods: Forty-eight female Wistar rats with cryoinjured hearts were randomized into non-treated normal (group-1, n=12), DMEM injected (group-2, n=10), myoblast-transplanted (group-3, n=12) and myoblast-hVEGF(165) (group-4, n=14). Ten days after cryoinjury, 200 microl DMEM containing 3x10(6) cells or without cells was injected into the injured myocardium.

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Objectives: We report in vitro functional assessment of human skeletal myoblasts with adenoviral bicistronic vector carrying human vascular endothelial growth factor-165 (hVEGF165) and angiopoietin-1 (Ang-1).

Methods: Myoblasts were assessed for their purity by desmin expression. A replication incompetent adenoviral bicistronic vector (Ad-Bic) carrying both hVEGF165 and Ang-1 was used for transduction of myoblasts.

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Bioengineering the regenerative heart may provide a novel treatment for heart failure. On May 14, 2002, a 55-year-old man suffering from ischemic myocardial infarction received 25 injections carrying 465 million cGMP-produced pure myoblasts into his myocardium after coronary artery bypass grafting. As on August 28, 2002, his EKG was normal and showed no arrhythmia.

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Bioengineering the regenerative heart may provide a novel treatment for heart failure. On May 14, 2002, a 55-year-old man suffering from ischemic myocardial infarction received 25 injections carrying 465 million cGMP-produced pure myoblasts into his myocardium after coronary artery bypass grafting. As on August 28, 2002, his EKG was normal and showed no arrhythmia.

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This study investigated the potential of human skeletal myoblast carrying human VEGF(165) for angiomyogenesis for cardiac repair. A porcine heart model of chronic infarction was created in 18 female swine by coronary artery ligation. The animals were randomized into: group 1, DMEM injected ( n=6), group 2, myoblast transplanted ( n=5) and group 3, VEGF(165) myoblast transplanted ( n=7).

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We report the transduction of human VEGF165 gene into human myoblast and characterization of the transduced myoblasts for transduction and expression efficiency. Human myoblasts were assessed by immunostaining for desmin expression. A replication incompetent adenoviral vector carrying human VEGF165 was constructed and used for transduction of myoblasts.

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