Drinkable in situ-forming tough hydrogels for gastrointestinal therapeutics

Pills are a cornerstone of medicine but can be challenging to swallow. While liquid formulations are easier to ingest, they lack the capacity to localize therapeutics with excipients nor act as controlled release devices. Here we describe drug formulations based on liquid in situ-forming tough (LIFT) hydrogels that bridge the advantages of solid and liquid dosage forms. LIFT hydrogels form directly in the stomach through sequential ingestion of a crosslinker solution of calcium and dithiol crosslinkers, followed by a drug-containing polymer solution of alginate and four-arm poly(ethylene glycol)-maleimide. We show that LIFT hydrogels robustly form in the stomachs of live rats and pigs, and are mechanically tough, biocompatible and safely cleared after 24 h. LIFT hydrogels deliver a total drug dose comparable to unencapsulated drug in a controlled manner, and protect encapsulated therapeutic enzymes and bacteria from gastric acid-mediated deactivation. Overall, LIFT hydrogels may expand access to advanced therapeutics for patients with difficulty swallowing.

[HIV infection rate, high-risk behavior and pre-exposure prophylaxis/post-exposure prophylaxis in men who have sex with men in Beijing]

Objective: To understand the incidence of HIV infection, high risk behaviors and pre-exposure prophylaxis/post-exposure prophylaxis (PrEP/PEP) utilization in men who have sex with men (MSM) in Beijing. Methods: Sample size was estimated to be 1 227 persons and 207 person year respectively in the survey and the cohort by using Epi Info 7.0 software. Using convenient sampling method, MSM were recruited by using Wechat app. Questionnaire was completed online to collect the information about demographic characteristics, high risk behavior, and utilization of PrEP/PEP of the MSM. MSM collected dry blood spot (DBS) samples by themselves, and mailed the DBS samples to laboratory for HIV nucleic acid testing. Open cohort was established and those with HIV negative nucleic acid testing results were followed up. Non-conditional binary logistic regression method was used to identify the associated factors for high risk anal sex in the last month and having multiple homosexual partners in the last month. Results: A total of 1 147 MSM were recruited, and follow up for 236 person years was conducted in 956 MSM with negative HIV nucleic acid testing results. The detection rate of new HIV infection was 1.3 per 100 person-years (3/236). During the last month, the proportions of consistent condom use in anal sex and oral sex were 50.7% (238/469) and 4.9% (23/469). In the MSM, 5.9% (43/723) had sex with HIV positive partners in the last month. 9.8% (103/1 049) used PrEP, and 8.7% (91/1 049) used PEP. The proportion of consistent condom use in PrEP and PEP were 34.3% (24/70) and 72.2% (39/54) respectively. Logistic regression analysis revealed that compared with those who used no PrEP/PEP, those who used PrEP/PEP were more likely to have unprotected anal sex in the last month (aOR=3.16, 95%CI:1.45-7.18), and more likely to have multiple homosexual partners in the last month (aOR=2.64, 95%CI:1.19-6.30), and compared with those who used no Rush Popper or drugs in the last month, those who used Rush Popper or drugs in the last month were more likely to have unprotected anal sex in the last month (aOR=2.34, 95%CI:1.67-3.30), and more likely to have multiple homosexual partners (aOR=2.42,95%CI:1.76-3.33). Conclusions: It is necessary to strengthen the health education to promote condom use and introduce the harm of drug use in MSM. In PrEP and PEP services, it is still necessary to suggest consistent condom use for MSM.

[Focusing on timing selection and whole-course management of liver transplantation treatment for patients with acute-on-chronic liver failure]

Acute-on-chronic liver failure (ACLF) is a clinical syndrome of acute decompensation accompanied by organ failure that occurs on the basis of chronic liver disease and has a high short-term mortality rate. Currently, there are still differences in relation to the definition of ACLF; thus, baseline characteristics and dynamic changes are important bases for clinical decision-making in patients with liver transplantation and others. The basic strategies for treating ACLF currently include internal medicine treatment, artificial liver support systems, and liver transplantation. Multidisciplinary active collaborative management throughout the whole course is of great significance for further improving the survival rate in patients with ACLF.

Lipid Nanoparticles for Nucleic Acid Delivery to Endothelial Cells

Endothelial cells play critical roles in circulatory homeostasis and are also the gateway to the major organs of the body. Dysfunction, injury, and gene expression profiles of these cells can cause, or are caused by, prevalent chronic diseases such as diabetes, cardiovascular disease, and cancer. Modulation of gene expression within endothelial cells could therefore be therapeutically strategic in treating longstanding disease challenges. Lipid nanoparticles (LNP) have emerged as potent, scalable, and tunable carrier systems for delivering nucleic acids, making them attractive vehicles for gene delivery to endothelial cells. Here, we discuss the functions of endothelial cells and highlight some receptors that are upregulated during health and disease. Examples and applications of DNA, mRNA, circRNA, saRNA, siRNA, shRNA, miRNA, and ASO delivery to endothelial cells and their targets are reviewed, as well as LNP composition and morphology, formulation strategies, target proteins, and biomechanical factors that modulate endothelial cell targeting. Finally, we discuss FDA-approved LNPs as well as LNPs that have been tested in clinical trials and their challenges, and provide some perspectives as to how to surmount those challenges.

[Progress in research of influencing factors of prophylaxis drug use after non-occupational exposure to HIV]

Non-occupational post-exposure prophylaxis (nPEP), a biological means to block the transmission of HIV, is recommended by European countries, USA and WHO to use in HIV high-risk groups, but its utilization rate is still very low. The information-motivation-behavioral skills model (IMB) can accurately explain the prevalence and change of health behaviors. Based on this model, this paper summarizes the progress in research of the influencing factors for nPEP use to provide a basis for further research to promote the use of nPEP.

[Establishment and validation of a predictive nomogram model for advanced gastric cancer with perineural invasion]

Objective: Peripheral nerve invasion (PNI) is associated with local recurrence and poor prognosis in patients with advanced gastric cancer. A risk-assessment model based on preoperative indicators for predicting PNI of gastric cancer may help to formulate a more reasonable and accurate individualized diagnosis and treatment plan. Methods: Inclusion criteria: (1) electronic gastroscopy and enhanced CT examination of the upper abdomen were performed before surgery; (2) radical gastric cancer surgery (D2 lymph node dissection, R0 resection) was performed; (3) no distant metastasis was confirmed before and during operation; (4) postoperative pathology showed an advanced gastric cancer (T2-4aN0-3M0), and the clinical data was complete. Those who had other malignant tumors at the same time or in the past, and received neoadjuvant radiochemotherapy or immunotherapy before surgery were excluded. In this retrospective case-control study, 550 patients with advanced gastric cancer who underwent curative gastrectomy between September 2017 and June 2019 were selected from the Affiliated Hospital of Qingdao University for modeling and internal verification, including 262 (47.6%) PNI positive and 288 (52.4%) PNI negative patients. According to the same standard, clinical data of 50 patients with advanced gastric cancer who underwent radical surgery from July to November 2019 in Qingdao Municipal Hospital were selected for external verification of the model. There were no statistically significant differences between the clinical data of internal verification and external verification (all P>0.05). Univariate analysis and multivariate logistic regression analysis were used to determine the independent risk factors for PNI in advanced gastric cancer, and the clinical indicators with statistically significant difference were used to establish a preoperative nomogram model through R software. The Bootstrap method was applied as internal verification to show the robustness of the model. The discrimination of the nomogram was determined by calculating the average consistency index (C-index). The calibration curve was used to evaluate the consistency of the predicted results with the actual results. The Hosmer-Lemeshow test was used to examine the goodness of fit of the discriminant model. During external verification, the corresponding C-index index was also calculated. The area under ROC curve (AUC) was used to evaluate the predictive ability of the nomogram in the internal verification and external verification groups. Results: A total of 550 patients were identified in this study, 262 (47.6%) of which had PNI. Multivariate logistic regression analysis revealed that carcinoembryonic antigen level ≥ 5 μg/L (OR=5.870, 95% CI: 3.281-10.502, P<0.001), tumor length ≥5 cm (OR=5.539,95% CI: 3.165-9.694, P<0.001), mixed Lauren classification (OR=2.611, 95%CI: 1.272-5.360, P=0.009), cT3 stage (OR=13.053, 95% CI: 5.612-30.361, P<0.001) and the presence of lymph node metastasis (OR=4.826, 95% CI: 2.729-8.533, P<0.001) were significant independent risk factors of PNI in advanced gastric cancer (all P<0.05). Based on these results, diffused Lauren classification and cT4 stage were included to establish a predictive nomogram model. CEA ≥ 5 μg/L was for 68 points, tumor length ≥ 5 cm was for 67 points, mixed Lauren classification was for 21 points, diffused Lauren classification was for 38 points, cT3 stage was for 75 points, cT4 stage was for 100 points, and lymph node metastasis was for 62 points. Adding the scores of all risk factors was total score, and the probability corresponding to the total score was the probability that the model predicted PNI in advanced gastric cancer before surgery. The internal verification result revealed that the AUC of nomogram was 0.935, which was superior than that of any single variable, such as CEA, Lauren classification, cT stage, tumor length and lymph node metastasis (AUC: 0.731, 0.595, 0.838, 0.757 and 0.802, respectively). The external verification result revealed the AUC of nomogram was 0.828. The C-ndex was 0.931 after internal verification. External verification showed a C-index of 0.828 from the model. The calibration curve showed that the predictive results were good in accordance with the actual results (P=0.415). Conclusion: A nomogram model constructed by CEA, tumor length, Lauren classification (mixed, diffuse), cT stage, and lymph node metastasis can predict the PNI of advanced gastric cancer before surgery.

Nanoparticles exhibit greater accumulation in kidney glomeruli during experimental glomerular kidney disease

Loss and dysfunction of glomerular podocytes result in increased macromolecule permeability through the glomerular filtration barrier and nephrotic syndrome. Current therapies can induce and maintain disease remission, but cause serious and chronic complications. Nanoparticle drug carriers could mitigate these side effects by delivering drugs to the kidneys more efficiently than free drug through tailoring of carrier properties. An important extrinsic factor of nanoparticle biodistribution is local pathophysiology, which may drive greater nanoparticle deposition in certain tissues. Here, we hypothesized that a "leakier" filtration barrier during glomerular kidney disease would increase nanoparticle distribution into the kidneys. We examined the effect of nanoparticle size and disease state on kidney accumulation in male BALB/c mice. The effect of size was tested using a panel of fluorescent polystyrene nanoparticles of size 20-200 nm, due to the relevance of this size range for drug delivery applications.Experimental focal segmental glomerulosclerosis was induced using an anti-podocyte antibody that causes abrupt podocyte depletion. Nanoparticles were modified with carboxymethyl-terminated poly(ethylene glycol) for stability and biocompatibility. After intravenous injection, fluorescence from nanoparticles of size 20 and 100 nm, but not 200 nm, was observed in kidney glomeruli and peritubular capillaries. During conditions of experimental focal segmental glomerulosclerosis, the number of fluorescent nanoparticle punctae in kidney glomeruli increased by 1.9-fold for 20 and 100 nm nanoparticles compared to normal conditions. These findings underscore the importance of understanding and leveraging kidney pathophysiology in engineering new, targeted drug carriers that accumulate more in diseased glomeruli to treat glomerular kidney disease.

[Application of convolutional neural network to risk evaluation of positive circumferential resection margin of rectal cancer by magnetic resonance imaging]

Objective: To explore the feasibility of using faster regional convolutional neural network (Faster R-CNN) to evaluate the status of circumferential resection margin (CRM) of rectal cancer in the magnetic resonance imaging (MRI). Methods: This study was registered in the Chinese Clinical Trial Registry (ChiCTR-1800017410). Case inclusion criteria: (1) the positive area of CRM was located between the plane of the levator ani, anal canal and peritoneal reflection; (2) rectal malignancy was confirmed by electronic colonoscopy and histopathological examination; (3) positive CRM was confirmed by postoperative pathology or preoperative high-resolution MRI. Exclusion criteria: patients after neoadjuvant therapy, recurrent cancer after surgery, poor quality images, giant tumor with extensive necrosis and tissue degeneration, and rectal tissue construction changes in previous pelvic surgery. According to the above criteria, MRI plain scan images of 350 patients with rectal cancer and positive CRM in The Affiliated Hospital of Qingdao University from July 2016 to June 2019 were collected. The patients were classified by gender and tumor position, and randomly assigned to the training group (300 cases) and the validation group (50 cases) at a ratio of 6:1 by computer random number method. The CRM positive region was identified on the T2WI image using the LabelImg software. The identified training group images were used to iteratively train and optimize parameters of the Faster R-CNN model until the network converged to obtain the best deep learning model. The test set data were used to evaluate the recognition performance of the artificial intelligence platform. The selected indicators included accuracy, sensitivity, positive predictive value, receiver operating characteristic (ROC) curves, areas under the ROC curves (AUC), and the time taken to identify a single image. Results: The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the CRM status determined by the trained Faster R-CNN artificial intelligence approach were 0.884, 0.857, 0.898, 0.807, and 0.926, respectively; the AUC was 0.934 (95% CI: 91.3% to 95.4%). The Faster R-CNN model's automatic recognition time for a single image was 0.2 s. Conclusion: The artificial intelligence model based on Faster R-CNN for the identification and segmentation of CRM-positive MRI images of rectal cancer is established, which can complete the risk assessment of CRM-positive areas caused by in-situ tumor invasion and has the application value of preliminary screening.

Optimized nonviral gene delivery for primary urinary renal progenitor cells to enhance cell migration

Progressive loss of glomerular podocytes during kidney disease leads to irreversible kidney failure, and is exacerbated by the fact that podocytes are terminally differentiated epithelial cells and unable to proliferate. Regeneration of lost podocytes must therefore derive from nonpodocyte sources. Human urine-derived renal progenitor cells (uRPCs) are attractive podocyte progenitors for cell therapy applications due to their availability from patient urine and ability to migrate to injured glomeruli and differentiate into de novo podocytes after intravenous administration. Because gene delivery has emerged as an important strategy to augment the functionality and survival of cell therapies prior to injection, in this work we optimized nonviral gene delivery conditions (cell density, DNA dose, % FBS, and transfection material composition) to primary uRPCs. Using the cationic polymer-peptide conjugate VIPER for gene delivery and the Sleeping Beauty transposon/transposase constructs for gene integration, we optimized transfection parameters to achieve efficient transgene expression (up to 55% transfected cells) and stable transgene expression (>65% integration efficiency) lasting up to 10 days. With these methods, we transfected uRPCs to overexpress CXCR4, an important chemokine receptor that mediates uRPC migration to the kidneys after intravenous injection, and demonstrate that CXCR4-uRPCs exhibit enhanced migration compared to mock-transfected cells.

[Establish a predictive modeling under antiviral therapy for hepatitis B e antigen seroconversion in chronic hepatitis B]

Objective: To explore the predictive factors by demonstrating a predictive modeling under antiviral therapy for hepatitis B e antigen seroconversion in HBeAg-positive chronic hepatitis B patients. Methods: 198 cases with HBeAg-positive chronic hepatitis B were enrolled. Fatty liver, family history of hepatitis B, age, sex, drinking history, HBsAg, HBeAg, HBV-DNA levels, total bilirubin (TBil), CD4/CD8, albumin (ALB), alanine amino transferase (ALT) levels were used as a predictor variables of HBeAg seroconversion. Serological seroconversion of HBeAg was observed at 144 weeks of antiviral therapy. Predictive factors of HBeAg seroconversion was analyzed by logistic regression analysis, and the receiver operating characteristic curve was plotted. Results: HBeAg seroconversion rate was 36.87%. Univariate analysis demonstrated that fatty liver (χ(2) = 35.377; P < 0.001), family history of hepatitis B (χ(2) = 15.687; P < 0.001), the levels of HBeAg (t = 5.034; P < 0.001), HBsAg (t = 3.454; P < 0.001) and HBV-DNA levels (Z = 4.651; P < 0.001) were predictor variables of HBeAg seroconversion. Multivariate analysis showed that family history of hepatitis B, fatty liver, HBV-DNA levels and HBeAg were independent predictors of HBeAg seroconversion. The established logistic regression model for HBeAg through regression analysis was logit P = 9.623-1.228 × family history of hepatitis B - 1.726 × fatty liver - 0.764 × HBV-DNA levels - 0.146 × HBeAg and area under curve was 0.875. When the cut-off value was -0.9350, the sensitivity and specificity were 92.70%, 75.50%, 83.22%, respectively. Conclusion: Family history of hepatitis B, fatty liver, HBV-DNA levels and HBeAg may be independent predictors of HBeAg seroconversion at 144 weeks of antiviral therapy in HBeAg-positive chronic hepatitis B patients.

Boronic acid copolymers for direct loading and acid-triggered release of Bis-T-23 in cultured podocytes

We report an acid-reversible linker for triggered release of Bis-T-23, an experimental small molecule drug for kidney disease treatment that restores podocyte morphology during disease. Bis-T-23 contains catechols, which form an acid-reversible, covalent boronate ester bond with boronic acids. We synthesized phenylboronic acid-containing polymers using reversible addition-fragmentation chain transfer polymerization that were able to directly load and solubilize Bis-T-23. Because of the reversibility of the boronic ester bond, drug was released in its native form in a pH-dependent manner. The polymers rapidly trafficked into acidic compartments and did not exhibit cytotoxicity, and polymer-drug conjugates successfully delivered Bis-T-23 into cultured podocytes.

[Measurement of morphological parameters of internal acousticmeatus using thin-section CT]

Objective: This study aimed to measure the morphological parameters of the internal acoustic meatus(IAM) and its adjacent structures using temporal-bone thin-section CT(computed tomography). Methods: CT images were obtained from 50 Chinese adult patients (25 males and 25 females, 100 sides) which had no visible lesion in the petrous part of the temporal bone and inner ear, the morphological parameters of all inner ear parts were sectionally measured on the specified plane using SPSS 22.0 software for statistical analysis. Results: The integral morphological characteristics of the IAM were observed. These results revealed that anterior-posterior diameter of the internal acoustic poer(IAP)(CD) was (6.93±1.85)mm, the superior-inferior diameter of the IAP(EF) was (4.40±0.86)mm, the length of the IAM(AB) was (9.30±1.60)mm, the superior-inferior diameter of the IAM(the intersection of inner 1/3 section and middle 1/3 section) was (4.13±0.83)mm, the superior-inferior diameter of the IAM(the intersection of middle 1/3 section and outer 1/3 section) was (4.61±1.02)mm, the anterior-posterior diameter of the IAM(the intersection of inner 1/3 section and middle 1/3 section) was (6.62±1.92)mm, the anterior-posterior diameter of the IAM(the intersection of middle 1/3 section and outer 1/3 section) was (6.28±1.65)mm, the depth of transverse crest (superior wall) was (3.10±0.75)mm, the depth of transverse crest (interior wall)the was (1.46±0.59)mm, the distance from transverse crest vertex A to the superior wall of the IAM was (2.05±0.42)mm, the distance from transverse crest vertex A to the interior wall of the IAM was (2.93±0.41)mm, the thickness of the superior bone wall of the IAM (the intersection of inner 1/3 section and middle 1/3 section) was (4.45±1.34)mm, the thickness of the superior bone wall of the IAM (the intersection of middle 1/3 section and outer 1/3 section) was (4.32±1.12)mm, the thickness of the superior bone wall of the IAM (the intersection of outer 1/3 section and transverse crest vertex) was (4.37±1.28)mm, and the appearance ratio of the cells in the whole IAM superior wall was 32%.The whole IAM assumed the shape of short cylinder, inclining about 1 cm outward, with the upper-lower diameter and anterior-posterior diameter about 5 mm. Conclusion: It is necessary for carrying out preoperative the temporal-bone thin-section CT to obtain the morphological parameters of the IAM, determine its basic morphology, and provide references to avoid damaging the other important structures during IAM surgeries.

Presence, distribution and molecular epidemiology of multi-drug-resistant Gram-negative bacilli from medical personnel of intensive care units in Tianjin, China, 2007-2015

BACKGROUND

Multi-drug-resistant Gram-negative bacteria (MDRGNB) have become an important cause of nosocomial infection in intensive care units (ICUs).

AIMS

To investigate the molecular epidemiology of MDRGNB isolated from medical personnel (MP) and non-medical personnel (NMP) at 69 ICUs in Tianjin, China.

METHODS

From April 2007 to October 2015, 2636 nasal and hand swab samples from 1185 MP and 133 NMP were cultured for GNB (including MDRGNB), meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The susceptibilities of GNB to 14 antimicrobial agents were determined, and 80 MDRGNB were characterized using pulsed-field gel electrophoresis (PFGE) and dendrogram analysis.

FINDINGS

In total, 301 GNB were identified in 269 MP, including 109 MDRGNB isolates in 104 MP. Forty-two GNB were isolated from 39 NMP, which included 20 NMP with MDRGNB. Overall, 8.8% of MP were colonized with MDRGNB, which greatly exceeded colonization rates with MRSA (0.9%) and VRE (0.1%). Three pairs of Klebsiella pneumoniae and one pair of Enterobacter aerogenes were indistinguishable from each other, but the majority of isolate tests had distinct PFGE profiles.

CONCLUSIONS

The prevalence of MDRGNB was high among ICU MP in Tianjin, and greatly exceeded that of VRE and MRSA. There was no difference in the rates of nasal carriage of MDRGNB between MP and NMP, but NMP were significantly more likely to have hand colonization with MDRGNB. PFGE profiles showed that there was only limited sharing of strains of MDR E. aerogenes and K. pneumoniae between personnel.

Efficient Identification of Murine M2 Macrophage Peptide Targeting Ligands by Phage Display and Next-Generation Sequencing

Peptide ligands are used to increase the specificity of drug carriers to their target cells and to facilitate intracellular delivery. One method to identify such peptide ligands, phage display, enables high-throughput screening of peptide libraries for ligands binding to therapeutic targets of interest. However, conventional methods for identifying target binders in a library by Sanger sequencing are low-throughput, labor-intensive, and provide a limited perspective (<0.01%) of the complete sequence space. Moreover, the small sample space can be dominated by nonspecific, preferentially amplifying "parasitic sequences" and plastic-binding sequences, which may lead to the identification of false positives or exclude the identification of target-binding sequences. To overcome these challenges, we employed next-generation Illumina sequencing to couple high-throughput screening and high-throughput sequencing, enabling more comprehensive access to the phage display library sequence space. In this work, we define the hallmarks of binding sequences in next-generation sequencing data, and develop a method that identifies several target-binding phage clones for murine, alternatively activated M2 macrophages with a high (100%) success rate: sequences and binding motifs were reproducibly present across biological replicates; binding motifs were identified across multiple unique sequences; and an unselected, amplified library accurately filtered out parasitic sequences. In addition, we validate the Multiple Em for Motif Elicitation tool as an efficient and principled means of discovering binding sequences.

Multiplexed gene transfer to a human T-cell line by combining Sleeping Beauty transposon system with methotrexate selection

Engineered human T-cells are a promising therapeutic modality for cancer immunotherapy. T-cells expressing chimeric antigen receptors combined with additional genes to enhance T-cell proliferation, survival, or tumor targeting may further improve efficacy but require multiple stable gene transfer events. Methods are therefore needed to increase production efficiency for multiplexed engineered cells. In this work, we demonstrate multiplexed, non-viral gene transfer to a human T-cell line with efficient selection (∼ 50%) of cells expressing up to three recombinant open reading frames. The efficient introduction of multiple genes to T-cells was achieved using the Sleeping Beauty transposon system delivered in minicircles by nucleofection. We demonstrate rapid selection for engineered cells using methotrexate (MTX) and a mutant human dihydrofolate reductase resistant to methotrexate-induced metabolic inhibition. Preferential amplification of cells expressing multiple transgenes was achieved by two successive rounds of increasing MTX concentration. This non-viral gene transfer method with MTX step selection can potentially be used in the generation of clinical-grade T-cells housing multiplexed genetic modifications.

A functionalized, injectable hydrogel for localized drug delivery with tunable thermosensitivity: synthesis and characterization of physical and toxicological properties

Thermosensitive injectable hydrogels have been used for the delivery of pharmacological and cellular therapies in a variety of soft tissue applications. A promising class of synthetic, injectable hydrogels based upon oligo(ethylene glycol) methacrylate (OEGMA) monomers has been previously reported, but these polymers lack reactive groups for covalent attachment of therapeutic molecules. In this work, thermosensitive, amine-reactive and amine-functionalized polymers were developed by incorporation of methacrylic acid N-hydroxysuccinimide ester or 2-aminoethyl methacrylate into OEGMA-based polymers. A model therapeutic peptide, bivalirudin, was conjugated to the amine-reactive hydrogel to investigate effects on the polymer thermosensitivity and gelation properties. The ability to tune the thermosensitivity of the polymer in order to compensate for peptide hydrophilicity and maintain gelation capability below physiological temperature was demonstrated. Cell encapsulation studies using an H9 T-cell line (CD4+) were conducted to evaluate feasibility of the hydrogel as a carrier for cellular therapies. Although this class of polymers is generally considered to be non-toxic, it was found that concentrations required for gelation were incompatible with cell survival. Investigation into the cause of cytotoxicity revealed that a hydrolysis byproduct, diethylene glycol monomethyl ether, is likely a contributing factor. While modifications to structure or composition will be required to enable viable cell encapsulation, the functionalized injectable hydrogel has the potential for controlled delivery of a wide range of drugs.

Andrographolide suppresses RANKL-induced osteoclastogenesis in vitro and prevents inflammatory bone loss in vivo

BACKGROUND AND PURPOSE

Osteoclasts play a pivotal role in diseases such as osteoporosis, rheumatoid arthritis and tumour bone metastasis. Thus, searching for natural compounds that may suppress osteoclast formation and/or function is promising for the treatment of osteoclast-related diseases. Here, we examined changes in osteoclastogenesis and LPS-induced osteolysis in response to andrographolide (AP), a diterpenoid lactone isolated from the traditional Chinese and Indian medicinal plant Andrographis paniculata.

EXPERIMENTAL APPROACH

Effects of AP on osteoclast differentiation and bone resorption were measured in vitro. Western blots and RT-PCR techniques were used to examine the underlying molecular mechanisms. The bone protective activity of AP in vivo was assessed in a mouse model of osteolysis.

KEY RESULTS

AP concentration-dependently suppressed RANKL-mediated osteoclast differentiation and bone resorption in vitro and reduced the expression of osteoclast-specific markers, including tartrate-resistant acid phosphatase, calcitonin receptors and cathepsin K. Further molecular analysis revealed that AP impaired RANKL-induced NF-κB signalling by inhibiting the phosphorylation of TGF-β-activated kinase 1, suppressing the phosphorylation and degradation of IκBα, and subsequently preventing the nuclear translocation of the NF-κB p65 subunit. AP also inhibited the ERK/MAPK signalling pathway without affecting p38 or JNK signalling.

CONCLUSIONS AND IMPLICATIONS

AP suppressed RANKL-induced osteoclastogenesis through attenuating NF-κB and ERK/MAPK signalling pathways in vitro, thus preventing bone loss in vivo. These data indicated that AP is a promising natural compound for the treatment of osteoclast-related bone diseases.

Alterations of fatty acid β-oxidation capability in the liver of ketotic cows

Dairy cows are highly susceptible to ketosis after parturition. In the present study, we evaluated the expression of fatty acid β-oxidation-related enzymes in the liver of ketotic (n=6) and nonketotic (n=6) cows. Serum levels of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and glucose were determined by using standard biochemical techniques. The mRNA abundance and protein content of acyl-CoA synthetase long-chain (ACSL), carnitine palmitoyltransferase I (CPT I), carnitine palmitoyltransferase II (CPT II), acyl-CoA dehydrogenase long chain (ACADL), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS), and acetyl-CoA carboxylase (ACC) were evaluated by real-time PCR and ELISA. We found that serum glucose levels were lower in ketotic cows than in nonketotic cows, but serum BHBA and NEFA concentrations were higher. Messenger RNA and protein levels of ACSL were significantly higher in livers of ketotic cows than those in nonketotic cows. In contrast, mRNA levels of CPT I and mRNA and protein levels of CPT II, ACADL, HMGCS, and ACC were decreased in the liver of ketotic cows. Serum NEFA concentration positively correlated with ACSL protein levels and negatively correlated with protein levels of CPT II, HMGCS, ACADL, and ACC. In addition, serum BHBA concentration negatively correlated with protein levels of CPT II, HMGCS, and ACADL. Overall, fatty acid β-oxidation capability was altered in the liver of ketotic compared with nonketotic cows. Furthermore, high serum NEFA and BHBA concentrations play key roles in affecting pathways of fatty acid metabolism in the liver.

Preparation of specific monoclonal antibodies against chelated copper ions

Copper ions are too small to elicit an immune response. Therefore, copper was conjugated to carrier proteins using S-2-(4-isothiocyanatobenzyl)-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid, a bifunctional chelator, to make artificial antigens for copper. Several mice were immunized, and monoclonal antibodies (MAbs) against chelated copper were produced. Spleen cells of immunized mice were fused with myeloma cells. The resulting hybridomas were screened using protein conjugates which were covalently bound to metal-free 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA) or Cu-DOTA. Two hybridoma cell lines (F4 and B2) that produced MAbs with high selectivity and sensitivity were expanded for further study. Cross-reactivities with other metals were below 1%. These antibodies were used to construct competitive ELISAs for copper ions. The IC(50) for F4 and B2 were 0.39 and 1.66 mg/l, respectively. The detection range and the lowest detection limit for copper using the antibody F4 was 0.019-8.22 and 0.003 mg/l, respectively. Spike recovery studies in tap water showed that the most sensitive antibody could be used for copper detection in drinking water.

Measurement of milk D-3-hydroxybutyrate with a simple UV spectrophotometer method: an alternative assay method

The measurement of D-3-hydroxybutyrate (D-BHBA) in milk samples is an important tool for diagnosis of subclinical/clinical ketosis in dairy cows. We describe a simple UV spectrophotometric method for measuring the concentration of D-BHBA in milk of dairy cows. From two herds, 119 milk samples were taken from dairy cows. The standard-curve equation was y = 0.2582x + 0.0269 (R2 = 0.9967). The assay was highly specific with a minimum detection limit of 0.01 mmol/L and measuring range of up to 5 mmol/L. The recovery was between 99.35% and 100.22% and repeatability was 99.8%. The comparison between the spectrophotometric method and the fluorometric method revealed a close correlation (r = 0.9939). These results show that the spectrophotometric method can be successfully used as an alternative method to measure D-BHBA content in milk.