Objective To test the releasing property of a self-developed plastic drug delivery implant of anti-infective nano-hydroxyapatite(nano-HA)so as to provide a new local drug delivery system(LDDS)for treatment of osteomyelitis.Methods The nano-HA was used as the core carrier to load gentamicin(GM).It was coated with poly hydroxybutyrate-co-hydroxyvalerate /polyethylene glycol(PHBV/PEG)to prepare the nano-HA-PHBV/PEG-GM microspheres which were mixed with the fibrin sealant(FS)to develop a plastic implant.Then its antibacte rial and in vitro releasing properties were investigated.Results The plastic LDDS implant was found to have a fine drug delivery capability.The bacterial growth inhibition zone was found around the LDDS for 56 days in the antibacterial test.Three samples were soaked with liquid of PBS(phosphate buffered saline).The titer of GM released within the first day was 154.3 ?g/mL,and then the releasing maintained a slow level in the following days.After 49 days'releasing,the titer was 6.9 ?g/mL which was still higher than the MIC(2 ?g/mL)(minima l inhibitory concentration)of GM.Conclusion The plastic LDDS has a fine in vitro releasing property and may have a widespread application in treatment of osteomyelitis.

BACKGROUND: Gentamicin bead chain is an effective drug delivery system for treatment of osteomyelitis, but it cannot be degraded, need to be removed by second operation, and can breed pathogens. As a result, biodegradable drug delivery systems become a hotspot. Nano-hydroxyapatite/poly(β-hydroxybutyrate-co-β-hydroxyvalerate)-polyethylene glycol-gentamicin (nano-HA/PHBV-PEG-GM-DDS) is considered to be a good choice for the current predicament. OBJECTIVE: To evaluate the acute or chronic toxic reactions of the whole body and local tissues, intracutaneous stimulation, cytotoxicity and hemolytic reactions after bone remodeling and implantation of nano-HA/PHBV-PEG-GM-DDS, thus providing a new kind of material for treating osteomyelitis. METHODS: Plastic nano-HA/PHBV-PEG-GM-DDS was prepared using plastic fibrin glue as microsphere scaffold and nano-HA as the core carrier of GM that was coated with PHBV and PEG. The acute, subacute/chronic toxicity, implantation, hemolysis, cytotoxicity and intracutaneous stimulation tests were performed according to the evaluated criteria of medical implanted materials as wel as biological and animal trials recommended in GB/T16886.1-1997. RESULTS AND CONCLUSION: The plastic nano-HA/PHBV-PEG-GM-DDS was nontoxic and caused no apparent changes in liver and kidney function and serum biochemical indexes. Pathological examination showed that the implanted material was covered with tissues, and inflammation changes accorded with the general regularity of inflammatory outcomes. After implantation, the nano-HA/PHBV-PEG-GM-DDS was biodegraded and replaced by osseous tissues. The hemolytic rate of the material extract to the composite diffusion solution was 1.2%, which was below the standard criteria (5%). Human bone marrow cells cultured in vitro with the plastic nano-HA/PHBV-PEG-GM-DDS grew normally with good morphology. There was no stimulation reaction according to the criteria after the diffusion solution was subcutaneously injected into the back of the animal. These findings indicate that the plastic nano-HA/PHBV-PEG-GM-DDS for treating osteomyelitis possesses excel ent biocompatibility and security.

Objective To investigate the growth of rabbit osteoblast on the composite bioactive glass material scaffolds and to explore the experimental methods of optimized material scaffolds in bone tissue engineering. Methods The mesenchymal stem cells(MSCs) were separated and cultured from rabbit thigh marrow,and they were induced and differentiated into osteoblast by the revulsant.The change of typical appearance of the MSCs was investigated under microscope.The cytological characteristics of the MSCs were observed through cells activity and immunohistochemistry method.The osteoblast was cocultured with three various bioactive glasses respectively.The compatibility between the various bioactive glasses and osteoblast was compared by observation of the changes of the cells.Results The MSCs were successfully induced and cultured in the presence of the osteoblast revulsant.After inducement,these cells displayed osteoblast-like morphology.The bioactive glass composite scaffolds supported the attachment of cultured rabbit osteoblast.These cells proliferated faster on scaffolds with higher poriness of 90.20% and 94.50% than with lower poriness of 75.90%.Conclusion It is feasible to use bioactive glass composite scaffolds with proper poriness for bone tissue engineering.

Objective:To investigate the application value of cystic plate approach (CPA) for extrahepatic right hepatic pedicle dissection in minimally invasive anatomical hepatectomy (MIALR).Methods:The retrospective cohort study was conducted. The clinicopathological data of 42 patients with primary liver cancer who underwent laparoscopic right hemi-hepatectomy in Nanfang Hospital of Southern Medical University from August 2020 to August 2022 were collected. There were 36 males and 6 females, aged (55±13)years. Of the 42 patients, 25 cases undergoing CPA for extrahepatic right hepatic pedicle dissection were divided into the CPA group, and 17 cases undergoing traditional approach for extrahepatic right hepatic pedicle dissection were divided into the traditional approach group. Observation indicators: (1) surgical situations; (2) postoperative situations. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( IQR), and comparison between groups was conducted using the Mann?Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi?square test or Fisher exact probability. Comparison of ordinal data was conducted using the non‐parameter rank sum test. Results:(1) Surgical situations. All patients in the two groups underwent laparoscopic right hemi-hepatectomy successfully, with the surgical margin as negative. The operative time, volume of intraoperative blood loss, time of dissection of the targeted hepatic pedicle, cases undergoing dissection of the trunk of right anterior hepatic pedicle and its operation time, cases undergoing dissection of the trunk of right posterior hepatic pedicle and its operation time, cases with hepatic pedicle injury, cases with hepatic tissue injury, cases with dissection space as large and small were 150.00(130.00)minutes, 100.00(100.00)mL, 472.00(201.00)seconds, 10 and 366.00(94.75)seconds, 9 and 564.00(138.50)seconds, 2, 2, 25, 0 in patients of the CPA group, versus 140.00(113.00)minutes, 100.00(125.00)mL, 670.00(107.00)seconds, 8 and 663.00(136.00)seconds, 7 and 783.00(189.00)seconds, 8, 5, 2, 19 in patients of the traditional approach group. There were significant differences in the time of dissection of the targeted hepatic pedicle, time of dissection of the trunk of right anterior hepatic pedicle, time of dissection of the trunk of right posterior hepatic pedicle, hepatic tissue injury, dissection space between the two groups ( Z=-4.809, -3.254, -3.188, χ2=6.493, 34.314, P<0.05) and there was no significant difference in the operation time, volume of intraoperative blood loss, dissection of the trunk of right anterior hepatic pedicle, dissection of the trunk of right posterior hepatic pedicle, hepatic tissue injury between the two groups ( Z=-0.282, -0.412, χ2=0.095, 0.002, 1.976, P>0.05). (2) Postoperative situations. There was no patient undergoing postoperative hemorrhage in both of the two groups. The alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBil) and prothrombin time (PT) at postoperative day 3, cases with postoperative biliary fistula, pathological type of tumor (hepatocellular carcinoma, intrahepatic cholangiocarcinoma) were 68.00(48.50)U/L, 52.00(35.50)U/L, 28.30(12.35)mmol/L, 12.40(2.40)seconds, 2, 21, 4 in patients of the CPA group. The above indicators were 58.00(25.00)U/L, 41.00(19.50)U/L, 26.80(14.25)mmol/L, 12.50(2.95)seconds, 5, 15, 2 in patients of the traditional approach group. There was no significant difference in the ALT, AST, TBil, PT at postoperative day 3, cases with postoperative biliary fistula between the two groups ( Z=-1.218, -1.488, -0.205, -0.320, χ2=1.976, P>0.05), and there was no significant difference in the pathological type of tumor between the two groups ( P>0.05). Conclusion:Application of CPA for extrahepatic right hepatic pedicle dissection in MIALR is safe and feasible.

Objective:To investigate the application value of cystic plate approach (CPA) for extrahepatic right hepatic pedicle dissection in minimally invasive anatomical hepatectomy (MIALR).Methods:The retrospective cohort study was conducted. The clinicopathological data of 42 patients with primary liver cancer who underwent laparoscopic right hemi-hepatectomy in Nanfang Hospital of Southern Medical University from August 2020 to August 2022 were collected. There were 36 males and 6 females, aged (55±13)years. Of the 42 patients, 25 cases undergoing CPA for extrahepatic right hepatic pedicle dissection were divided into the CPA group, and 17 cases undergoing traditional approach for extrahepatic right hepatic pedicle dissection were divided into the traditional approach group. Observation indicators: (1) surgical situations; (2) postoperative situations. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( IQR), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data was conducted using the non‐parameter rank sum test. Results:(1) Surgical situations. All patients in the two groups underwent laparos-copic right hemi-hepatectomy successfully, with the surgical margin as negative. The operation time, volume of intraoperative blood loss, time of dissection of the targeted hepatic pedicle, cases under-going dissection of the trunk of right anterior hepatic pedicle and its operation time, cases under-going dissection of the trunk of right posterior hepatic pedicle and its operation time, cases with hepatic pedicle injury, cases with hepatic tissue injury, cases with dissection space as large and small were 150.00(130.00)minutes, 100.00(100.00)mL, 472.00(201.00)seconds, 10 and 366.00(94.75)seconds, 9 and 564.00(138.50)seconds, 2, 2, 25, 0 in patients of the CPA group, versus 140.00(113.00)minutes, 100.00(125.00)mL, 670.00(107.00)seconds, 8 and 663.00(136.00)seconds, 7 and 783.00(189.00)seconds, 8, 5, 2, 19 in patients of the traditional approach group. There were significant differences in the time of dissection of the targeted hepatic pedicle, time of dissection of the trunk of right anterior hepatic pedicle, time of dissection of the trunk of right posterior hepatic pedicle, hepatic pedicle injury, dissection space between the two groups ( Z=-4.809, -3.254, -3.188, χ2=6.493, 34.314, P<0.05) and there was no significant difference in the operation time, volume of intraoperative blood loss, dissection of the trunk of right anterior hepatic pedicle, dissection of the trunk of right posterior hepatic pedicle, hepatic tissue injury between the two groups ( Z=-0.282, -0.412, χ2=0.095, 0.002, 1.976, P>0.05). (2) Postoperative situations. There was no patient under-going postoperative hemorrhage in both of the two groups. The alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBil) and prothrombin time (PT) at postoperative day 3, cases with postoperative biliary fistula, pathological type of tumor (hepatocellular carcinoma, intrahepatic cholangiocarcinoma) were 68.00(48.50)U/L, 52.00(35.50)U/L, 28.30(12.35)mmol/L, 12.40(2.40)seconds, 2, 21, 4 in patients of the CPA group. The above indicators were 58.00(25.00)U/L, 41.00(19.50)U/L, 26.80(14.25)mmol/L, 12.50(2.95)seconds, 5, 15, 2 in patients of the traditional approach group. There was no significant difference in the ALT, AST, TBil, PT at postoperative day 3, postoperative biliary fistula between the two groups ( Z=-1.218, -1.488, -0.205, -0.320, χ2=1.976, P>0.05), and there was no significant difference in the pathological type of tumor between the two groups ( P>0.05). Conclusion:Application of CPA for extrahepatic right hepatic pedicle dissection in MIALR is safe and feasible.