Biomedical subjects

Xiuqiong Li

Publications and source records attributed to Xiuqiong Li.

8 recordsLinked to original sources

PubMed2003

Effects of baicalin-modified poly(D,L-lactic acid) surface on the behavior of osteoblasts.

In the present study, the functions of rat calvaria osteoblasts on baicalin-modified poly(D,L-lactic acid) (PDLLA) films were investigated in vitro. The surface characteristics of surfaces (both modified and control) were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). Cell morphologies on these surfaces were examined by scanning electron microscopy (SEM). Cell adhesion and proliferation were used to assess cell growth on the modified and control surfaces. The MTT assay was used to determine cell viability and alkaline phosphatase (ALP) activity was performed to evaluate differentiated cell function. Compared to control films, cell attachment of osteoblasts on baicalin-modified PDLLA film was significantly higher (P<0.05 and P<0.01) after 6 h and 8 h culture, and cell proliferation was also significantly greater (P<0.05 and P<0.01) at the end of 4th and 7th day, respectively. The MTT assay suggested that the cell viability of osteoblasts cultured on baicalin-modified PDLLA film was significantly higher (P<0.05) than that seeded on the control. Meanwhile, the ALP activity of osteoblasts cultured on modified films was also considerably enhanced (P<0.01) compared to that found on control. These results revealed that the biocompatibility PDLLA could be improved by surface modification with baicalin.

Journal Article↗

PubMed2002

Surface modification of poly (D,L-lactic acid) with chitosan and its effects on the culture of osteoblasts in vitro.

Chitosan is a good biodegradable natural polymer, widely used in biomedical fields. In this study, chitosan was used to modify the surface of poly (D,L-lactic acid) (PDLLA) in order to enhance its cell affinity. The properties of a modified PDLLA surface and control were investigated by contact angle and electron spectroscopy for chemical analysis (ESCA), which indicated the changes in surface energy and chemical structure. Scanning electron microscopy (SEM) observation displayed differences in surface morphology between the chitosan-modified film and the control. These data reflected that PDLLA films could be modified with chitosan and in turn may affect the biocompatibility of the modified films. Therefore, adhesion and growth of osteoblasts on modified PDLLA films as well as control were studied. Cell morphologies on the films were examined by SEM and cell viability was evaluated using an MTT assay; the differentiated cell function was assessed by measuring alkaline phosphatase (ALP) activity. The ALP activity of modified PDLLA films was significantly higher than that found on the control (p < 0.01). The proliferation of osteoblasts on modified films was also found to be higher than that on the control (p < 0.05), suggesting that chitosan could be used to modify PDLLA and then enhance its cell biocompatibility.

Alkaline Phosphatase↗

PubMed2002

Improvement of the functions of osteoblasts seeded on modified poly(D,L-lactic acid) with poly(aspartic acid).

One of the challenges in the field of tissue engineering is the development of biomaterial/cell interactions. For the purposes of the present study, two molecular weights of poly(aspartic acid) (PASP) were used to modify poly(D,L-lactic acid) (PDLLA) films in order to enhance their cell affinity. The properties of the PDLLA-modified surfaces and the controls were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). These data reflect the change in the biocompatibility of modified PDLLA surfaces. Then rat osteoblasts were seeded onto these modified surfaces and on controls to examine their effects on cell adhesion and proliferation. Cell morphologies on these surfaces were studied by scanning electron microscopy (SEM), and cell viability was evaluated with a MTT assay. In addition, differentiated cell function was assessed by measuring alkaline phosphatase (ALP) activity. The results suggest that PASP-modified surfaces may enhance the interactions between osteoblasts and PDLLA films.

Alkaline Phosphatase↗

PubMed2002

Poly(D,L-lactic acid) surfaces modified by silk fibroin: effects on the culture of osteoblast in vitro.

The objective of this study was to modify the surface of poly(D,L-lactic acid) (PDLLA) with different molecular weight of silk fibroins, and assess the effects of the modified surfaces on the functions of rat osteoblasts cultured in vitro. The properties of the modified PDLLA surface and the control one were investigated by contact angle and electron spectroscopy for chemical analysis (ESCA). The former indicated the variation of hydrophilicity and the latter suggested that the modified PDLLA film using silk fibroin is enriched with nitrogen atoms. The biocompatibility of the PDLLA film may be altered and in turn affects the seeded cell functions. Therefore, attachment and proliferation of osteoblasts seeded on the modified PDLLA films and the control one were examined. Cell morphologies on these films were studied by scanning electron microscopy (SEM) and cell viability was evaluated by MTT assay. In addition, differentiated cell function was assessed by measuring the alkaline phosphatase (ALP) activity. These results suggest that the silk fibroin-modified PDLLA surface can improve the interaction between osteoblasts and the PDLLA films.

Alkaline Phosphatase↗

PubMed2002

Influence of different surface modification treatments on poly(D,L-lactic acid) with silk fibroin and their effects on the culture of osteoblast in vitro.

The objective of this study was to investigate the efficiency of two treatments for poly(D,L-lactic acid) (PDLLA) surface modification using silk fibroin. one chemical treatment and one physical treatment: 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (WSC) and entrapment. The properties of control films, WSC-modified and entrapment-treated PDLLA films were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). The water-contact angle measurement indicated the change of hydrophilicity and the ESCA analysis suggested that the modified PDLLA film using silk fibroin became enriched with nitrogen atoms. The biocompatibility of PDLLA film might be altered, which in turn would affect the functions of cells that were seeded on it. Therefore, attachment and proliferation of osteoblasts that were seeded on modified PDLLA films and control films were examined. Cell viability was evaluated by the MTT assay and differentiated cell function was assessed by measuring alkaline phosphatase activity. These results suggested that silk fibroin was used to modify PDLLA surface via WSC and that entrapment could improve the interactions between osteoblasts and PDLLA films. The entrapment treatment was more effective thin WSC treatment to accomplish the goal of surface modification.

Alkaline Phosphatase↗

PubMed2002

Modulation of osteoblast function using poly(D,L-lactic acid) surfaces modified with alkylation derivative of chitosan.

Poly(D,L-lactic acid) (PDLLA) was modified with alkylated chitosan (N-butyl chitosan and N-cetyl chitosan), and the effects of modified films on the functions of rat osteoblasts were investigated. The characteristics of surfaces (both modified and control) were examined by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). Cell morphologies on these surfaces were taken using scanning electron microscopy (SEM). Cell attachment and proliferation were used to assess cell behavior on modified surface and control. MTT assay was used to determined cell viability, and alkaline phosphatase (ALP) activity was taken to evaluate differentiated cell function. Compared with the untreated films, no significant difference in cell attachment of osteoblasts was found on the modified films at a period of 8 h (p > 0.05). However, cell proliferation of N-butyl chitosan rather than N-cetyl chitosan modified PDLLA films was significantly higher than that found on control one (p < 0.05) at the end of the 4th and 7th days. The cell viability of osteoblasts on N-butyl chitosan modified PDLLA films were found higher than that on control (p < 0.05). These results suggested that N-butyl chitosan contributed greater than N-cetyl chitosan when used to modify PDLLA films for improving its biocompatibility.

Alkaline Phosphatase↗

PubMed2002

[A tissue-engineered strain scaffold for three-dimensional cell cultures].

This article introduces a three-dimensional scaffold which is used to perform three-dimensional cell culture under mechanical stretch from the point of construction of tissue-engineered tissue. The composition, structure, surface characteristics, mechanical property, and cell compatibility of the scaffold have been studied by using surface chemistry and material mechanics testing methods. The results indicate that the polyvinyl alcohol (PVA) sponge, which is water-tolerant, coated with Poly-DL-lactic-co-glycolic acid (PLGA) possesses a good nature in appropriate surface feature, porosity, elastic recoil, and cell compatibility. These features provide wide options for using this scaffold to study the effects of mechanical stretch on cells maintained in three-dimensional culture to provide a three-dimensional matrix.

Biocompatible Materials↗

PubMed2002

[Initial study on three-dimensional culture of tenocytes under cyclic mechanical stretch].

OBJECTIVE: To detect the effect of mechanical stretch on shape, alignment, proliferation, and metabolism of tendon cells maintained in three-dimensional culture. METHODS: A cyclic mechanical strain apparatus for three-dimensional cell cultures was developed. Based on the apparatus, a specific stretch pattern (10% elongation, 12 stretches/min for 15 min of each hour) was applied to tenocytes-scaffolding composites. RESULTS: Initial studies demonstrated that the stretch-mediated effects on cell division, DNA synthesis, and metabolism in such cultures were influenced by the amplitude, frequency, periodicity, and duration of the applied stretch. After 48 hours' exposure to the stretch, the cell number and [3H] thymidine incorporation into DNA were increased, compared with those of the nonstretched controls(P < 0.05). Under the stretch pattern, the shape of cells changed to oblate and spread to the direction of the stretch. The cyclic stretch also caused an increase in collagen synthesis by tendon cells (P < 0.05), which was predominant in type I. CONCLUSION: Cyclic mechanical stretches act directly to stimulate tendon cell growth and these results are compatible with a significant role for stretch in tissue-engineered tendon construction.

Cell Division↗