Medicine and Health Sciences Commons^™

Developing An Artificial Fallopian Tube: Successful In Vitro Trials In Mice., Stephen Hunter, J. Neeld, J. Scott, D. Olsen, R. Urry, T. Cichocki

Stephen K. Hunter

This report describes the design and testing of an artificial fallopian tube for the treatment of tubal infertility. Within the device, mouse eggs incubated with sperm were fertilized and a microinfusion pump was used to transport the fertilized ova through the tube. Normal offspring resulted from transfer of the developing embryos into pseudopregnant recipients. These results provide encouraging evidence that an artificial fallopian tube warrants further investigation as a potential alternative to in vitro fertilization.

The Gamete And Embryo Compatibility Of Various Synthetic Polymers., Stephen Hunter, J. Scott, D. Hull, R. Urry

Stephen K. Hunter

Several popular and well-characterized polymeric materials were evaluated for their biocompatibility toward the cells unique to reproduction. To accomplish these studies, several in vitro tests were developed that evaluated biocompatibility between the polymers and spermatozoa, ova, and embryos. The data indicated significant differences between the materials with respect to their biocompatibility toward sperm motility, the sperm's ability to penetrate zona-free hamster eggs, and the ability of two-cell mouse embryos to divide. Polytetrafluoroethylene (PTFE-Teflon; PTFE, Chemplast Inc., Wayne, NJ), polyethylene glycol (PEG), and polyhydroxyethyl methacrylate (PHEMA) appear to be the most inert of the materials studied. Polyvinyl chloride (PVC; Tygon-Norton, Akron, …

Surface Modification Of Polyurethane To Promote Long-Term Patency Of Peritoneal Access Devices., Stephen Hunter, D. Gregonis, D. Coleman, B. Hanover, R. Stephen, S. Jacobsen

Stephen K. Hunter

No abstract provided.

Cell Encapsulation As A Potential Nondietary Therapy For Maternal Phenylketonuria, Donna Santillan, Mark Santillan, Stephen Hunter

Stephen K. Hunter

OBJECTIVE: The objective of this work was to determine whether cells overexpressing phenylalanine (Phe) hydroxylase (PAH) can significantly reduce Phe in vitro for potential use as a therapy for preventing maternal phenylketonuria. STUDY DESIGN: Human 293T and WRL68 cell lines were transiently and stably transfected to overexpress PAH. Cells were encapsulated within microspheres of sodium alginate. Timed measurements of Phe in media were performed using tandem mass spectrometry. RESULTS: Both nonencapsulated and encapsulated transiently transfected cells overexpressing PAH significantly reduced the Phe concentration in media by approximately 50% in comparison to mock-transfected cells. Cell line clones stably expressing PAH significantly …

Biodegradable Microspheres Containing Group B Streptococcus Vaccine: Immune Response In Mice, Stephen Hunter, M. Andracki, A. Krieg

Stephen K. Hunter

OBJECTIVE: This study seeks to show the feasibility of producing a group B Streptococcus (GBS) vaccine, which is capable of producing both a local IgA immune response at the mucosal surface where GBS is colonized and a humoral IgG response, which is capable of transplacental passive immunization. STUDY DESIGN: Inactivated GBS antigen was microencapsulated in poly (D, L-lactic-co-glycolic acid) (PLG) with a water-in-oil-in-water double emulsion technique. Immunostimulatory synthetic oligodeoxynucleotides containing cytidine-phosphate-guanosine (CpG) motifs were coencapsulated as a potent adjuvant. The ICR strain of mouse was used in these studies. Female mice with normal immune systems were immunized with the PLG …

Encapsulated Beta-Islet Cells As A Bioartificial Pancreas To Treat Insulin-Dependent Diabetes During Pregnancy, Stephen Hunter, Y. Wang, C. Weiner, Jennifer Niebyl

Stephen K. Hunter

OBJECTIVE: Our purpose was to determine the effectiveness of the bioartificial pancreas technique in correcting (1) maternal carbohydrate metabolism and (2) fetal malformation rates in a pregnant diabetic animal model. STUDY DESIGN: Insulin secretion from encapsulated rat islets cultured in the presence of homologous rat prolactin was determined and compared with that of controls. Streptozotocin-induced diabetic Balb/c mice were then transplanted with rat islet cells encapsulated within alginate microbeads and were then bred. Blood glucose determinations were made after transplantation and throughout gestation. Pups were delivered by cesarean section on day 19 of gestation. Outcome parameters from the transplanted study …

Efficacy Of Polymeric Encapsulated C5a Peptidase-Based Group B Streptococcus Vaccines In A Murine Model., Donna Santillan, Karishma K Rai, Mark Santillan, Yogita Krishnamachari, Aliasger K Salem, Stephen Hunter

Stephen K. Hunter

OBJECTIVE: The purpose was to examine in mice the efficacy of various polymeric-encapsulated C5a peptidase vaccine formulations in eliciting a long-term immune response and preventing group B streptococcus (GBS) infection. STUDY DESIGN: C5a peptidase was encapsulated in semipermeable microspheres of poly(lactide-coglycolide) (PLGA). Female ICR mice were immunized with 0, 10, or 30 μg of encapsulated C5a peptidase within 2 different formulations of PLGA polymers. Booster doses were given at weeks 4 and 8. Antibody responses were measured by enzyme-linked immunosorbent assay at weeks 4, 8, 11, and 40. Vaginal challenges with GBS types 1a, III, and V were performed at …

Protective Immunization In Mice Against Group B Streptococci Using Encapsulated C5a Peptidase, Donna Santillan, M. Andracki, Stephen Hunter

Stephen K. Hunter

OBJECTIVE: The purpose of the study was to test whether C5a peptidase encapsulated within a biodegradable polymer can act as a vaccine and elicit an immune response to prevent group B streptococci (GBS) infection in mice and provide protection to pups. STUDY DESIGN: C5a peptidase was encapsulated in semipermeable microspheres of poly(lactide-co-glycolide). Female ICR mice were immunized with encapsulated C5a peptidase, free C5a peptidase, or empty microparticles. Booster doses were given at days 21 and 42. Antibody responses were measured by enzyme-linked immunosorbent assay. Challenge with GBS type III was performed 4 days after the final booster in the vaginal …

Cell Encapsulation As A Potential Nondietary Therapy For Maternal Phenylketonuria., Donna Santillan, Mark Santillan, Stephen Hunter

Stephen K. Hunter

OBJECTIVE: The objective of this work was to determine whether cells overexpressing phenylalanine (Phe) hydroxylase (PAH) can significantly reduce Phe in vitro for potential use as a therapy for preventing maternal phenylketonuria.

STUDY DESIGN: Human 293T and WRL68 cell lines were transiently and stably transfected to overexpress PAH. Cells were encapsulated within microspheres of sodium alginate. Timed measurements of Phe in media were performed using tandem mass spectrometry.

RESULTS: Both nonencapsulated and encapsulated transiently transfected cells overexpressing PAH significantly reduced the Phe concentration in media by approximately 50% in comparison to mock-transfected cells. Cell line clones stably expressing PAH significantly …

Bioartificial Pancreas Use In Diabetic Pregnancy, Stephen Hunter, Y. Wang, V. Rodgers

Stephen K. Hunter

The purpose of this study was to evaluate the feasibility and effectiveness of Bioartificial Pancreas (BAP) technology use during diabetic pregnancy. In particular, the study asked 1) can microencapsulated islet cells effectively correct carbohydrate metabolism during diabetic pregnancy and 2) will such therapy, if initiated before conception, eliminate diabetes-induced congenital malformations in the fetus? Streptozotocin-induced diabetic female mice (ICR) received transplants of rat islets encapsulated within alginate microbeads. Animals were placed with male mice and bred. Random, nonfasting blood glucose (BG) determinations were made posttransplantation and throughout pregnancy. Pups were delivered by cesarean section on day 19 of gestation. Outcome …

Mathematical Modeling Of Myoglobin Facilitated Transport Of Oxygen In Devices Containing Myoglobin-Expressing Cells, H. Tilakaratne, Stephen Hunter, V. Rodgers

Stephen K. Hunter

Low pO(2) is perhaps the most significant factor in artificial pancreas failure. In these environments, not only is the beta cell production of insulin reduced, but the cell death rate is also significantly higher. Mathematical models are developed to test the feasibility of facilitated oxygen transport in enhancing O(2) flux to genetically engineered cells in a bioartificial device such as a pancreas. For this device, it is proposed that beta cells be genetically engineered to express myoglobin throughout the cell. In addition, the significance of including myoglobin throughout the alginate matrix present to provide immuno-protection for the transplanted cells is …