Preparation and efficacy of antibacterial methacrylate monomer-based polymethyl methacrylate bone cement containing N-halamine compounds.

Introduction: Our objective in this study was to prepare a novel type of polymethyl methacrylate (PMMA) bone cement, analyze its material properties, and evaluate its safety and antibacterial efficacy. Methods: A halamine compound methacrylate antibacterial PMMA bone cement containing an N-Cl bond structure was formulated, and its material characterization was determined with Fourier transform infrared spectroscopy (FT-IR) and 1H-NMR. The antibacterial properties of the material were studied using contact bacteriostasis and releasing-type bacteriostasis experiments. Finally, in vitro and in vivo biocompatibility experiments were performed to analyze the toxic effects of the material on mice and embryonic osteoblast precursor cells (MC3T3-E1). Results: Incorporation of the antibacterial methacrylate monomer with the N-halamine compound in the new antibacterial PMMA bone cement significantly increased its contact and releasing-type bacteriostatic performance against Staphylococcus aureus. Notably, at 20% and 25% additions of N-halamine compound, the contact and releasing-type bacteriostasis rates of bone cement samples reached 100% (p < 0.001). Furthermore, the new antibacterial bone cement containing 5%, 10%, and 15% N-halamine compounds showed good biocompatibility in vitro and in vivo. Conclusion: In this study, we found that the novel antibacterial PMMA bone cement with N-halamine compound methacrylate demonstrated good contact and releasing-type bacteriostatic properties against S. aureus. In particular, bone cement containing a 15% N-halamine monomer exhibited strong antibacterial properties and good in vitro and in vivo biocompatibility.

Injectable isoniazid-loaded bone cement based on hydrazone bonds achieving long-term release and decent mechanical properties.

A robust and easily manufactured high-strength and long-term release hydrazone-based isoniazid acrylic (HIA) bone cement is reported. The mechanical strength of HIA bone cement is similar to that of normal polymethyl methacrylate (PMMA) bone cement, far surpassing that of traditional isoniazid-containing antibiotic-loaded bone cement (INH bone cement). Isoniazid is connected to the bone cement through bioorthogonal hydrazone chemistry, and it possesses release properties superior to those of INH bone cement, allowing for the sustained release of isoniazid for up to 12 weeks. In vivo and in vitro studies also indicate that HIA cement exhibits better biocompatibility than INH bone cement. The results of this study not only signify progress in the realm of antimicrobial bone cement for addressing bone tuberculosis but also enhance our capacity to create and comprehend high-performing antimicrobial bone cement.

Investigating the in vitro antibacterial efficacy of composite bone cement incorporating natural product-based monomers and gentamicin.

OBJECTIVE: The objective of this study is to investigate the impact of four natural product extracts, namely, aloe-emodin, quercetin, curcumin, and tannic acid, on the in vitro bacteriostatic properties and biocompatibility of gentamicin-loaded bone cement and to establish an experimental groundwork supporting the clinical utility of antibiotic-loaded bone cements (ALBC). METHODS: Based on the components, the bone cement samples were categorized as follows: the gentamicin combined with aloe-emodin group, the gentamicin combined with quercetin group, the gentamicin combined with curcumin group, the gentamicin combined with tannic acid group, the gentamicin group, the aloe-emodin group, the quercetin group, the curcumin group, and the tannic acid group. Using the disk diffusion test, we investigated the antibacterial properties of the bone cement material against Staphylococcus aureus (n = 4). We tested cell toxicity and proliferation using the cell counting kit-8 (CCK-8) and examined the biocompatibility of bone cement materials. RESULTS: The combination of gentamicin with the four natural product extracts resulted in significantly larger diameters of inhibition zones compared to gentamicin alone, and the difference was statistically significant (P < 0.05). Except for the groups containing tannic acid, cells in all other groups showed good proliferation across varying time intervals without displaying significant cytotoxicity (P < 0.05). CONCLUSION: In this study, aloe-emodin, quercetin, curcumin, and tannic acid were capable of enhancing the in vitro antibacterial performance of gentamicin-loaded bone cement against S. aureus. While the groups containing tannic acid displayed moderate cytotoxicity in in vitro cell culture, all other groups showed no discernible cytotoxic effects.

CCL2 Knockdown Attenuates Inflammatory Response After Spinal Cord Injury Through the PI3K/Akt Signaling Pathway: Bioinformatics Analysis and Experimental Validation.

Spinal cord injury (SCI) is a common clinical problem in orthopedics with a lack of effective treatments and drug targets. In the present study, we performed bioinformatic analysis of SCI datasets GSE464 and GSE45006 in the Gene Expression Omnibus (GEO) public database and experimentally validated CCL2 expression in an animal model of SCI. This was followed by stimulation of PC-12 cells using hydrogen peroxide to construct a cellular model of SCI. CCL2 expression was knocked down using small interfering RNA (si-CCL2), and PI3K signaling pathway inhibitors and activators were used to validate and observe the changes in downstream inflammation. Through data mining, we found that the inflammatory chemokine CCL2 and PI3K/Akt signaling pathways after SCI expression were significantly increased, and after peroxide stimulation of PC-12 cells with CCL2 knockdown, their downstream cellular inflammatory factor levels were decreased. The PI3K/Akt signaling pathway was blocked by PI3K inhibitors, and the downstream inflammatory response was suppressed. In contrast, when PI3K activators were used, the inflammatory response was enhanced, indicating that the CCL2-PI3K/Akt signaling pathway plays a key role in the regulation of the inflammatory response. This study revealed that the inflammatory chemokine CCL2 can regulate the inflammatory response of PC-12 cells through the PI3K/Akt signaling pathway, and blocking the expression of the inflammatory chemokine CCL2 may be a promising strategy for the treatment of secondary injury after SCI.

Identification of the CCL2 PI3K/Akt axis involved in autophagy and apoptosis after spinal cord injury.

Spinal cord injury (SCI) is a devastating neurological disease with no cure that usually results in irreversible loss of sensory and voluntary motor functions below the injury site. We conducted an in-depth bioinformatics analysis combining the gene expression omnibus spinal cord injury database and the autophagy database and found that the expression of the autophagy gene CCL2 was significantly upregulated and the PI3K/Akt/mTOR signaling pathway was activated after SCI. The results of the bioinformatics analysis were verified by constructing animal and cellular models of SCI. We then used small interfering RNA to inhibit the expression of CCL2 and PI3K to inhibit and activate the PI3K/Akt/mTOR signaling pathway; western blot, immunofluorescence, monodansylcadaverine, and cell flow techniques were used to detect the expression of key proteins involved in downstream autophagy and apoptosis. We found that when PI3K inhibitors were activated, apoptosis decreased, the levels of autophagy-positive proteins LC3-I/LC3-II and Bcl-1 increased, the levels of autophagy-negative protein P62 decreased, the levels of pro-apoptotic proteins Bax and caspase-3 decreased, the levels of the apoptosis-inhibiting protein Bcl-2 increased. In contrast, when a PI3K activator was used, autophagy was inhibited, and apoptosis was increased. This study revealed the effect of CCL2 on autophagy and apoptosis after SCI through the PI3K/Akt/mTOR signaling pathway. By blocking the expression of the autophagy-related gene CCL2, the autophagic protective response can be activated, and apoptosis can be inhibited, which may be a promising strategy for the treatment of SCI.

Biliverdin Protects the Isolated Rat Lungs from Ischemia-reperfusion Injury via Antioxidative, Anti-inflammatory and Anti-apoptotic Effects.

BACKGROUND: Biliverdin (BV) has a protective role against ischemia-reperfusion injury (IRI). However, the protective role and potential mechanisms of BV on lung IRI (LIRI) remain to be elucidated. Thus, we aimed to investigate the protective role and potential mechanisms of BV on LIRI. METHODS: Lungs were isolated from Sprague-Dawley rats to establish an ex vivo LIRI model. After an initial 15 min stabilization period, the isolated lungs were subjected to ischemia for 60 min, followed by 90 min of reperfusion with or without BV treatment. RESULTS: Lungs in the I/R group exhibited significant decrease in tidal volume (1.44 ± 0.23 ml/min in I/R group vs. 2.41 ± 0.31 ml/min in sham group; P< 0.001), lung compliance (0.27 ± 0.06 ml/cmH2O in I/R group vs. 0.44 ± 0.09 ml/cmH2O in sham group; P< 0.001; 1 cmH2O=0.098 kPa), and oxygen partial pressure (PaO2) levels (64.12 ± 12 mmHg in I/R group vs. 114 ± 8.0 mmHg in sham group; P< 0.001; 1 mmHg = 0.133 kPa). In contrast, these parameters in the BV group (2.27 ± 0.37 ml/min of tidal volume, 0.41 ± 0.10 ml/cmH2O of compliance, and 98.7 ± 9.7 mmHg of PaO2) were significantly higher compared with the I/R group (P = 0.004, P< 0.001, and P< 0.001, respectively). Compared to the I/R group, the contents of superoxide dismutase were significantly higher (47.07 ± 7.91 U/mg protein vs. 33.84 ± 10.15 U/mg protein; P = 0.005) while the wet/dry weight ratio (P < 0.01), methane dicarboxylic aldehyde (1.92 ± 0.25 nmol/mg protein vs. 2.67 ± 0.46 nmol/mg protein; P< 0.001), and adenosine triphosphate contents (297.05 ± 47.45 nmol/mg protein vs. 208.09 ± 29.11 nmol/mg protein; P = 0.005) were markedly lower in BV-treated lungs. Histological analysis revealed that BV alleviated LIRI. Furthermore, the expression of inflammatory cytokines (interleukin-1ß, interleukin-6, and tumor necrosis factor-ß) was downregulated and the expression of cyclooxygenase-2, inducible nitric oxide synthase, and Jun N-terminal kinase was significantly reduced in BV group (all P< 0.01 compared to I/R group). Finally, the apoptosis index in the BV group was significantly decreased (P < 0.01 compared to I/R group). CONCLUSION: BV protects lung IRI through its antioxidative, anti-inflammatory, and anti-apoptotic effects.

Induction chemotherapy followed by concurrent chemoradiation and nimotuzumab for locoregionally advanced nasopharyngeal carcinoma: preliminary results from a phase II clinical trial.

Overexpression of epidermal growth factor receptor can be found in more than 80% of patients with locoregionally advanced nasopharyngeal carcinoma and is associated with shorter survival. In this work, we evaluated the feasibility of adding nimotuzumab to chemoradiation in locoregionally advanced nasopharyngeal carcinoma. Twenty-three patients with clinically staged T3-4 or any node-positive disease were enrolled. They were scheduled to receive one cycle of induction chemotherapy followed by intensity-modulated radiotherapy, weekly administration of nimotuzumab and concurrent chemotherapy. Results showed that all patients received a full course of radiotherapy, 19(82.6%)patients completed the scheduled neoadjuvant and concurrent chemotherapy, and 22(95.7%) patients received ≥6 weeks of nimotuzumab. During the period of concurrent chemoradiation and nimotuzumab, grade 3-4 toxicities occurred in 14(60.9%) patients: 8 (34.8%) had grade 3-4 oral mucositis, 6(26.1%) had grade 3 neutropenia, and 1(4.3%) had grade 3 dermatitis. No acne-like rash was observed. With a median follow-up of 24.1 months, the 2-year progression-free survival and overall survival were 83.5% and 95.0%, respectively. In conclusion, concurrent administration of chemoradiation and nimotuzumab was well-tolerated with good compliance. Preliminary clinical outcome data appear encouraging with favorable normal tissue toxicity results comparing with historical data of concurrent chemoradiation plus cetuximab.

Kinetic resolution of racemic styrene oxide at a high concentration by recombinant Aspergillus usamii epoxide hydrolase in an n-hexanol/buffer biphasic system.

Using the cell-free extract of engineered E. coli/Aueh2, expressing the recombinant Aspergillus usamii epoxide hydrolase (reAuEH2), as a biocatalyst, the kinetic resolution technique of racemic styrene oxide (rac-SO) was examined. In a phosphate buffer system (50mM, pH 7.0), 200mM rac-SO was efficiently resolved, obtaining (S)-SO with 98.1% enantiomeric excess (e.e.), whereas (S)-SO only with 45.2% e.e. was obtained from 750mM rac-SO. The analytical results verified that reAuEH2 shows tolerance towards high substrate concentration but is inactivated at a product concentration of 300mM. To produce (S)-SO with the high concentration, e.e. and volumetric productivity, n-hexanol was selected from a variety of water-miscible and water-immiscible organic solvents to construct an n-hexanol/buffer biphasic system. The optimal phase volume ratio, substrate over enzyme ratio and temperature were 1:1 (v/v), 6:1 (w/w) and 25°C, respectively. In an optimized biocatalytic system, a gram-scale resolution of rac-SO at a high concentration of 1M (120g/L) was performed at 25°C for 2h, obtaining (S)-SO with 98.2% e.e., 34.3% yield (maximum yield of 50%). The substrate concentration and volumetric productivity (1M, 20.6g/L/h) in a biphasic system significantly increased compared with those (0.2M, 3.1g/L/h) in a phosphate buffer system. The efficient resolution of rac-SO at a high concentration in a biphasic system makes it a promising technique for preparing a highly value-added enantiopure (S)-SO with high volumetric productivity.

Caffeic acid phenethyl ester attenuates ionize radiation-induced intestinal injury through modulation of oxidative stress, apoptosis and p38MAPK in rats.

Caffeic acid phenyl ester (CAPE) is a potent anti-inflammatory agent and it can eliminate the free radicals. This study aimed to investigate the radioprotective effects of CAPE on X-ray irradiation induced intestinal injury in rats. Rats were intragastrically administered with 10 µmol/kg/d CAPE for 7 consecutive days before exposing them to a single dose of X-ray irradiation (9Gy) to abdomen. Rats were sacrificed 72 h after exposure to radiation. We found that pretreatment with CAPE effectively attenuated intestinal pathology changes, apoptosis, oxidative stress, bacterial translocation, the content of nitric oxide and myeloperoxidase as well as the concentration of plasma tumor necrosis factor-α. Pretreatment with CAPE also reversed the activation of p38MAPK and the increased expression of intercellular cell adhesion molecule-1 induced by radiation in intestinal mucosa. Taken together, these results suggest that pretreatment with CAPE could be a promising candidate for treating radiation-induced intestinal injury.

Osseous metastasis of cutaneous squamous cell carcinoma treated successfully with oxaliplatin, tegafur and leucovorin combination chemotherapy: a case report.

Bone metastasis from cutaneous squamous cell carcinoma (SCC) is rare. We report a case of cutaneous SCC which was diagnosed by the presence of bone metastasis and treated with combination chemotherapy. A 53 year male had tissue contusion and persistent ulcer in the multiple regions of body for about 30 years and treat with Chinese Herbal Drugs in several hospitals, however, did not thorough cure. He was referred to our hospital for a dermatological examination in March 2009. Excisional biopsy and positron emission tomography-computed tomography (PET-CT) scan showed an invasive cutaneous SCC concomitant bone metastasis. Surgical treatment is limited, because of multiple cancerous ulcer and metastatic spreading. Therefore, we proceed to treat with oxaliplatin, tegafur and leucovorin (LV) combination chemotherapy and other adjuvant therapy. About 5 months following chemotherapy, the general situation of the patient was improved. Further cycle of chemotherapy resulted in complete disappearance of the tumor masses (confirmed by PET-CT). So far, there was no evidence of local recurrence or distant metastasis. This report indicates that the combination chemotherapy of oxaliplatin, tegafur and LV seems to have a considerable therapeutic effect for cutaneous SCC concomitant malignant bone metastasis.

[Treatment of medial malleolus fractures with closed reduction and percutaneous internal fixation].

OBJECTIVE: To study clinical effects of minimally invasive, effective and economic operational method for the treatment of medial malleolus fractures. METHODS: From March 2008 to August 2010, 19 patients (12 males and 7 females, ranging in age from 17 to 42 years, averaged 31.7 years) with medial malleolus fractures were reviewed. Closed reduction and percutaneous internal fixation were applied, with a hollow compression screw inserted at the centre and perpendicularly to the fracture surface. A Kirschner wire was inserted through the cortical bone of opposite side and in accordance with the axis of inner malleolus. Postoperative therapeutic effect was evaluated by Kaikkonen sprained ankle scoring system and imageology examination. RESULTS: All the patients got primary healing of incisions and were followed up, the duration ranged from 6 to 30 months, with an average of 18.7 months. All the patients obtained bone union. Clinical healing time ranged from 2.6 to 3.8 months, averaged 3.2 months. According to Kaikkonen scoring system, the results were rated as excellent in 5 cases, good in 10 cases, moderate in 3 cases, and poor in 1 case. CONCLUSION: It is a minimally invasive, effective and economic method to treat medial malleolus fractures by closed reduction and percutaneous internal fixation with hollow compression screw and Kirschner wire.

Invasion and control of water hyacinth (Eichhornia crassipes) in China.

By the time of primary 21st century, water hyacinth had become a serious environmental problem in China. Water hyacinth contributes to the major part of ecological hazards from the invasion of foreign plant species, which is estimated about USD 7 billion a year in values. In the past 10 years, herbicides glyphosate, 2,4-D and paraquat have been used in controlling water hyacinth in China. Although the herbicides provided effective control on the weed in some areas, they could not provide the sustainable inhibition on the weed population, while would lead to pollution of water at various levels. At present, the herbicide application on water hyacinth is forbidden in many areas of China such as Shanghai. In this situation, the asexual reproduction inhibitor, KWH02, was invented for controlling water hyacinth and it provided about 70% of growth inhibition without any risk of dead plant pollution. It has been about 10 years for bio-control of water hyacinth in China. Works focused on mainly the efficacy and safety of the utilization of foreign insects. Researches on microorganism herbicides to control water hyacinth were started and obtained primary achievements in recent years. Although there are different opinion on how to face the water hyacinth problem in China, it is accepted widely that the control methods should be high efficient and safe with low cost. Some practical measures for integrated management of water hyacinth are suggested.

[Template design of tissue flaps for covering auricular cage in one-stage total auricular reconstruction].

OBJECTIVE: To study the template design of tissue flaps for covering auricular cage in order to acquire accurate and reliable design method. METHODS: By the theory of engineering drawing and three-dimensional measuring on CT image, three dimensional configuration of 40 auricular surfaces were expanded approximately, and the character of them was analysed for the template design. RESULTS: It is similar of the expanded graphs of auricular surface three dimensional configuration in healthy persons, and simplified template of tissue flaps is drawn based on the key points of the above graph. CONCLUSIONS: CT three-dimensional measurement of auricular surface configuration can be used to design the template of tissue flaps for covering auricular cage, and can provide accurate and reliable template of tissue flaps for clinics.