The Effects of Local and Systemic Administration of Proline on Wound Healing in Rats.

Purpose: Wound healing consists of a sequence of complex molecular and cellular events. Collagen is composed mainly of proline and hydroxyproline. Proline and hydroxyproline constitute 1/3 of the amino acids in collagen, which makes up approximately 30% of the proteins within the body. The hydroxylation of proline found in collagen determines the stability of the triple helical structure of collagen. In this study, we examined the effects of local and systemic administration of proline on wound healing. Materials and Methods: 24 female Sprague-Dawley rats were used in the study and divided into three groups. Group 1: The defect created in the backs of the subjects was left to secondary healing. Group 2: 200 µl proline per day was administered topically for 30 days on the defect in the backs of the subjects. Group 3: 200 µl per day was administered intraperitoneally for 30 days on the defect in the backs of the subjects. Results: On day 21, there was a statistically significant difference between the groups in terms of the mean re-epithelialization score. On days 7 and 14, there was a statistically significant difference between the groups in terms of the mean granulation score. On days 7, 14, and 21, there was a statistically significant difference between the groups in terms of the mean collagen accumulation score. On day 30, there was a statistically significant difference between Groups 1 and 3 in terms of the mean E-mode score on mechanical tensile test. Conclusion: Our study confirmed that proline has positive effects on wound healing. However, it revealed that systemic administration of proline is more effective than local administration of proline.

Determining the most suitable costal cartilage level for rhinoplasty: an experimental study.

OBJECTIVE: The aim of this study was to compare the biomechanical properties of septal cartilage (SC) and costal cartilage (CC) grafts harvested from different ribs and to find at which level CC has characteristics closest to SC. STUDY DESIGN: Experimental cadaver study. SETTING: Istanbul Training and Research Hospital. MATERIAL AND METHOD: Cartilage grafts were harvested from the 6th, 7th, and 8th ribs and the SC of 10 fresh cadavers. Shaped cartilage grafts were subjected to a bending test. Results were measured, and the force-deflection curve was plotted. Flexural strength (σ(f)) and flexural modulus of elasticity (E(f)) were determined. Fractured surfaces were evaluated by scanning electron microscopy (SEM). RESULTS: According to F(max), it was determined that ribs 6, 7, and 8 have significantly more durability compared with the SC (Ps = .030, .004, and .001). With regard to deflection, there was no significant difference between the SC and the 6th and 7th ribs and between the 6th and 7th ribs (Ps = 1.000, .088, and .306), while a significant difference was found between the SC and the 8th rib (P = .001). According to σ(f), no differences were seen between the 6th and 7th rib (P = .782), while difference was detected between the 6th and 8th and the 7th and 8th ribs (p = .001). Similar trends were established in E(f) values as in σ(f.) These results were confirmed by SEM images. CONCLUSION: The 7th CC can be used as autograft because it shows similar properties to SC. However, the 6th CC is preferred if more flexibility is desired, and the 8th CC is preferred where more strength is needed.

Tensile characteristics of costal and septal cartilages used as graft materials.

OBJECTIVES: To determine the biomechanical characteristics of septal cartilage (SC) and costal cartilage (CC) taken from fresh cadavers using tensile testing and to establish CC graft material of a suitable thickness (ie, with tensile characteristics closest to those of SC). METHODS: Grafts of varying thickness were harvested from the central part of the seventh-rib CC and SC of 18 fresh cadavers. Tensile testing was performed with a 0.5-kilonewton load calibrated at 7 mm/min. The results were shown as a force-elongation curve. RESULTS: No significant difference according to tensile force was observed between the SC group and the 1.0-mm and 1.5-mm CC groups (P = .09 and P = .32, respectively). However, a significant difference was observed between the SC group and the 2.0-mm CC group (P = .04). Although the strength value of the CC group was 5.03 MPa, the modulus of elasticity was 1.33 MPa. In the SC group, the strength value was 12.42, but the modulus of elasticity was 1.39 MPa. The strength value of the SC group was higher than that of the CC group (P = .001), but the modulus of elasticity value of the CC group was higher than that of the SC group (P = .001). CONCLUSIONS: From the standpoint of tensile testing for preparing columellar struts, 1.0-mm and 1.5-mm CC have similar characteristics to SC and thus can be used instead of it. However, it is important to determine the thickness of CC by considering the expected characteristics of the established material and the forces that affect the area in the nose where the graft will be placed.