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Biomedical subjects

G Vozzi

Publications and source records attributed to G Vozzi.

11 recordsLinked to original sources
PubMed2007

Microfabrication of fractal polymeric structures for capillary morphogenesis: applications in therapeutic angiogenesis and in the engineering of vascularized tissue.

Microfabrication techniques were combined with fractal algorithms to realize polymeric scaffolds resembling capillary networks. The scaffolds were seeded with human endothelial cells in monoculture as well as in coculture with human fibroblasts. To enhance the process of angiogenesis, endothelial cells were transfected with an adenoviral vector carrying the gene for human tissue kallikrien. The results demonstrate that both the presence of a structured scaffold as well as fibroblasts in coculture contribute synergically to the promotion of a metabolically active network. The fractal scaffolds have several possible applications for example in vascularized tissue engineering and therapeutic angiogenesis. A broader implication of these results is that cell-extra cellular matrix and cell-cell interactions cooperate dynamically both at a biochemical as well as microstructural level.

Algorithms↗
PubMed2006

Endothelial cell function on 2D and 3D micro-fabricated polymer scaffolds: applications in cardiovascular tissue engineering.

Polymeric structures of a polylactide-polycaprolactone blend were micro-fabricated using the Pressure Assisted Microsyringe (PAM) system. Human umbilical vein endothelial cells were cultured on the scaffolds, and apoptosis, cell adhesion, proliferation and metabolism were evaluated. In addition, more specific indicators of endothelial cell function, namely nitric oxide and endothelin production, were also assessed. Thin films of the blend, as well as gelatine-coated glass slides (as controls) were used. The results show that as far as adhesion, apoptosis and metabolism are concerned, the scaffolds do not interfere with cell function compared with gelatin controls. However, the nitric oxide/endothelin ratio was higher than that observed on the gelatin films, suggesting that the scaffolds could be used for engineering small diameter blood vessels without risk of occlusion.

Cardiovascular System↗
PubMed2004

Microfabricated fractal branching networks.

In this article, we demonstrate how a combination of engineering and biological techniques could lead to the realization of branched microstructures that can be used for the repair of damaged vascularized tissue. Recursive "treelike" networks were first generated by using fractal algorithms based on Murray's equation for vascular branching as well as allometric scaling rules. Two- and three-dimensional branching patterns with different levels of complexity were then microfabricated from poly-lactide-co-glycolide (PLGA) by using the pressure-assisted microsyringe (PAM) system developed in our laboratory. Human endothelial cells isolated from umbilical cords were seeded on the microfabricated branched scaffolds to evaluate their effectiveness in supporting site-specific cell adhesion. The results show that cell densities on the networks increase with complexity up to the sixth level and are then constant independent of branching level. The implications of this finding are discussed in terms of contact inhibition of "capillaries."

Algorithms↗
PubMed2004

A feasibility study of yarns and fibers with annexed electronic functions: the ARIANNE project.

In this paper several issues concerning the development of fibers endowed with electronic functions will be presented and discussed. In particular, issues concerning materials, structures, electronic models and the mechanical constraints due to textile technologies will be detailed. All these aspects have been studied in the framework of the project ARIANNE, funded by the European Community during the V Frame Programme.

Biosensing Techniques↗
PubMed2002

Microsyringe-based deposition of two-dimensional and three-dimensional polymer scaffolds with a well-defined geometry for application to tissue engineering.

A technique for controlled deposition of biomaterials and cells in specific and complex architectures is described. It employs a highly accurate three-dimensional micropositioning system with a pressure-controlled syringe to deposit biopolymer structures with a lateral resolution of 5 microm. The pressure-activated microsyringe is equipped with a fine-bore exit needle and a wide variety of two- and three-dimensional patterns on which cells to be deposited can adhere. The system has been characterized in terms of deposition parameters such as applied pressure, motor speed, line width and height, and polymer viscosity, and a fluid dynamic model simulating the deposition process has been developed, allowing an accurate prediction of the topological characteristics of the polymer structures.

Biocompatible Materials↗
PubMed2001

Endothelial cell adhesion on bioerodable polymers.

This paper presents the results of a preliminary screening of a new class of bioerodable polymers, partial esters of alternating copolymers of maleic anhydride and mono-methoxyoligoethyleneglycol vinyl ethers (PAM) for use in engineered vascular tissue. Different initial concentrations of PAM and human serum albumin (HSA) were spin-coated onto glass substrates and the surface properties of the resulting films and their relationship to endothelial cell adhesion was examined. An optimum PAM/HSA blend for use as the cell contact surface of a bioerodable scaffold was identified.

Journal Article↗
PubMed1999

Antepartum computerized CTG and neonatal acid-base status at birth.

OBJECTIVE: To assess the correlation between individual computerized cardiotocography (cCTG) variables and acid-base status at birth before the first breathing in uncomplicated term pregnancy delivered by cesarean section. STUDY DESIGN: A retrospective cohort study. SUBJECTS AND METHODS: Seventy singleton normal pregnancies delivered by elective cesarean section. The last antepartum cCTG performed within 4 h from delivery by the System 8002 (Oxford Sonicaid, UK) was correlated to umbilical blood gas analysis (UBGA) values (AVL compact 2 analyser). Considering blood gas analysis values as dependent and individual cCTG parameters as independent variables the best regression subsets followed by a backward stepwise linear regression was used. RESULTS: There was no significant correlation of cCTG parameters with any of the values of blood gas analysis. However, when neonatal conditions, as expressed by arterial pH > 7.20, Becf > - 4.0 mmol/l and Apgar score at 5 min > 7, were taken as an end-point, they could be predicted by Acc15 and FM/hour (sensitivity: 35%, positive predictive value: 92%, cut-off > 7 and 67%, 92%, > 21, respectively). CONCLUSION: In uncomplicated pregnancies, the prospect of a vigorous newborn seems particularly associated with the presence of Acc > 15 and FM/hour > 21.

Acid-Base Equilibrium↗
PubMed1996

An obstetric and neonatal study on unplanned deliveries before arrival at hospital.

OBJECTIVE: To establish the prevalence of unplanned deliveries before arrival at a big metropolitan hospital and to determine the demographic characteristics of the group of women at risk of delivering before arrival. DESIGN: A random case control study. Each baby born before arrival and its mother were compared to the next baby born in the same Department. SUBJECTS: All babies born before arrival at the Department of Obstetrics and Gynecology, University "La Sapienza" in a 10 yr. period (Jan 1983-Dec 1993). RESULTS: Of 27,274 consecutive deliveries in the study period, 22 (0.8%) babies were born before arrival at hospital. Of the 22 women who delivered before arrival, 16 were Italian, 5 were considered nomad (no fixed address) and one was a Polish tourist. No statistical difference was found between groups regarding maternal age, parity, gestational age, birth weight and immediate delivery complications. No mortality cases were observed in the study or control group. Neonatal stay in the neonatal ward was longer in the study group (6.5 vs 3.5 days, P < 0.001). Hypothermia was the highest morbidity (P < 0.001) and neonatal complications were more prevalent in babies delivered before arrival than in-born babies (P < 0.001). CONCLUSIONS: Delivery before arrival to hospital does not seem to carry a higher neonatal mortality risk. However, the prevalence of complications was higher in such babies, with hypothermia being the highest morbidity.

Academic Medical Centers↗
PubMed1995

Clinical and ultrasonographic implications of uterine leiomyomatosis in pregnancy.

OBJECTIVE: To study the complications related to leiomyomatosis in pregnancy by clinical and ultrasonographic assessment. DESIGN: A retrospective study. SUBJECTS: All pregnancies admitted to the 2nd Institute of Gynecology and Obstetrics, Policlinico Umberto I, in the period between January 1992 to December 1993 were surveyed. RESULTS: Gestational age at the time of ultrasonographic neoplasm diagnosis was 25.1 +/- 13.4 weeks, 'we found no correlation between maternal age or parity affecting pregnancy outcome, Leiomyomatosis complicated pregnancy rate was 1.68%. Myomatosis was diagnosed clinically in 25 of 67 cases (37.3%). Regarding the location of the neoplasm, 59% was located in the corpus-uteri, 21% was considered a diffuse neoplasm and the 14% was located in the fundus. Threatened abortion was the most frequent complication (20%), abortion was the second (16.4%). We observed an increased abortion threat rate (p < 0.001) in those cases where the leiomyoma was in relation with the placenta. We had a surgery rate of 76% in pregnancies complicated by myomatosis, and the indication for surgery was given either primarily or exclusively by the presence of myomatous formation in 19 cases (50%). CONCLUSIONS: Our study suggests that location of the leiomyoma in relation to the placenta is a higher risk factor than its size, and that there is a higher risk for threats of abortion and abortion rates in pregnancies complicated by leiomyomatosis. We recommend that every pregnant woman with a suspected myoma should be ultrasonographically scanned.

Adult↗
PubMed1994

The cholesterol to phospholipids ratio (C/PL) of the erythrocyte membrane in normotensive, hypertensive pregnant and in cord blood as assessed by a simple enzymatic method.

The study described was conducted to evaluate a simple enzymatic method for the study of the cholesterol/phospholipids ratio in erythrocyte membrane (C/PL) in a group of normal pregnant, of hypertensive pregnant, in non-pregnant controls and in cord blood. Subjects consisted of 28 normotensive pregnant women (NT), 14 women with pregnancy induced hypertension (PIH), 10 non-pregnant normotensive women (Non-Preg) and 14 samples obtained from umbilical cord (C) at delivery from normotensive pregnant. Red blood cells were isolated from heparinated blood samples. Lipids were extracted from erythrocytes by isopropanol/chloroform, without preparation of cell ghosts. Cholesterol content was evaluated by cholesterol oxidase and phospholipids were estimated as organic phosphorus in the total lipid extract. We found a significant difference of C/PL between the PIH group and the NT group (1.01, SD 0.11 vs. 0.76, SD 0.10, 95% CI 0.74-0.78; p < 0.001) and the Non-Preg group (0.83, SD 0.11, 95% CI 0.80-0.86; p < 0.001). Cord blood C/PL was significantly elevated with respect to NT (1.25, SD 0.13 vs. 0.76, SD 0.10; p < 0.001). The method was proven to be fast, reliable and of value for the study of the pathophysiology of the alteration of the lipid composition, i.e., the increased cholesterol content, of the red cell membrane found in hypertensive pregnant patients.

Adult↗