Animal Safety Test of Bacillus thuringiensis BT Protein

[Objectives]To determine the biological safety of BT protein from Bacillus thuringiensis(Bt)fermentation broth to mammals at high doses.[Methods]Healthy mice were randomly divided into 4 groups with 10 mice in each group.The experimental groups were fed with Bt fermentation supernatant at 0.2,0.6 and 1.0 mL/kg,respectively,once a day for 7 consecutive days.The blank control group was fed normally without intragastric administration.[Results]There was no significant difference in blood routine and blood biochemical analysis between the experimental group and the control group.After intragastric administration,the mice were dissected,and no obvious pathological changes were found;the heart,liver,spleen,lung and kidney were taken to make tissue sections,and no pathological changes were found by microscopic observation.[Conclusions]Mice can tolerate high doses of BT protein from B.thuringiensis fermentation broth.

Biological Safety Evaluation of White Insect Tea in Guizhou

[Objective] The biological safety of white insect tea in Xifeng County of Guizhou Province was evaluated in order to provide a scientific basis for the development of white insect tea. [Method] Acute toxicity test in mice, Ames microbiological test and mouse bone marrow polychromatic erythrocyte micronucleus test were done with wild white inset tea produced in Xifeng County. At the same time, the contents of six kinds of limit pollutants were determined, including Pb,Cr,Cd,Hg,As,and F-. [Result] The results showed that white insect tea had LD505.0 g/kg（BW）in acute toxicity test, negative response in Ames test and microkernel test. In addition, the contents of Pb,Cr,Cd,Hg,As,and F- in the white inset tea were 2.20,1.06,0.46,0.09,0.71,21.50 mg/kg, much less than the national standard of tea （GB2762-2005,NY 659-2003）. [Conclusion] The white insect tea produced in Xifeng County of Guizhou Province is non-toxic, and good for human as beverage.

Spinal cord biological safety of image-guided radiation therapy versus conventional radiation therapy

Tumor models were simulated in purebred Beagles at the T9-10 levels of the spinal cord and treated with spinal image-guided radiation therapy or conventional radiation therapy with 50 or 70 Gy total radiation. Three months after radiation, neuronal injury at the T9-10 levels was observed, including reversible injury induced by spinal image-guided radiation therapy and apoptosis induced by conventional radiation therapy. The number of apoptotic cells and expression of the proapoptotic protein Fas were significantly reduced, but expression of the anti-apoptotic protein heat shock protein 70 was significantly increased after image-guided radiation therapy compared with the conventional method of the same radiation dose. Moreover, the spinal cord cell apoptotic index positively correlated with the ratio of Fas/heat shock protein 70. These findings indicate that 3 months of radiation therapy can induce a late response in the spinal cord to radiation therapy; image-guided radiation therapy is safer and results in less neuronal injury compared with conventional radiation therapy.

Research of the Application of Nanometer Materials in Sports Engineering and the Biological Safety

In the modern material engineering, the use of nanometer materials has entered the highly and intensively utilized stage, so new nanometer materials have been continuously found to replace the traditional ordinary materials. The so-called nanometer materials have the size within l - 100nm in thickness, which originates from the 1980s. At that time, nanometer materials didn＇t have a proper development due to the economic level. t towever, with the support of science and technology, this technology has undergone tremendous changes in the related fields. There have been increasing expansion in the kinds and the width in use of the nanometer materials, so have the research of nanometer materials. In this paper, we will briefly analyze the application ofnanometer materials in the sports engineering.

Emerging role of dual biologic therapy for the treatment of inflammatory bowel disease

Biologic agents have now been used in the management of inflammatory bowel disease(IBD)for many years where experience,expertise and confidence in their use has developed over time.In the United Kingdom,there are well established guidelines and recommendations for both single agent biologic treatments,and with combination therapy of a biologic agent with a small molecule agent in maintenance therapy.In recent times,there has been increasing interest and experience using dual biologic therapy(DBT)in IBD,primarily in difficult to treat and refractory cases with high disease burden.However,published data on use,experience and safety profiles is limited and large-scale studies remain low in number in this developing area.We therefore aim to present a summary and review of the available published data in this area to help us better understand the emerging role of DBT in IBD.

A biological safety evaluation on reclaimed water reused as scenic water using a bioassay battery

An assessment method based on three toxicity tests （algae growth inhibition, daphnia immobilization and larval fish toxicity） was used to screen the biological safety of reclaimed water which was reused as sole replenishment for scenic water system in a park （SOF Park） in northern China. A total of 24 water samples were collected from six sites of water system in the SOF Park in four different seasons. The results indicated that： （1） the reclaimed water directly discharged from a reclamation treatment plant near the SOF Park as influent of park had relatively low biological safety （all samples were ranked as C or D）; （2） the biological safety of reclaimed water was improved greatly with the ecological reclamation treatment processes composing of artificial wetland system and followed oxidation pond system; （3） the biological safety of reclaimed water in the main lake of SOF Park kept at a health status during different seasons （all samples were ranked as A）; （4） there was some certain correlation （R2= 0.5737） between the sum of toxicity scores and dissolved organic carbon for the studied water samples. It was concluded that the assessment method was reliable to screen the safety of reclaimed water reused as scenic water, and the reclaimed water with further ecological purification processes such as artificial wetland and oxidation pond system can be safely reused as scenic water in park.

Study of biological safety of scaffold material with heterologous deproteinized bone

To evaluate the biological safety of manufactured heterologous deproteinized bone and to provide an experimental basis for clinical applications. Methods ： Deproteinized bone （ 10 mm） and leaching liquor were made from pig ribs with a series of physical and chemical methods, then were evaluated through acute and subacute toxicity test, hemolysis test, pyrogen test, intracutaneous test, intramuscular implantation test and cytotoxity test. Results ： No obvious toxicity, hemolysis, pyrogenic characteristics, skin irritation, inflammatory reaction after intramusclar implantation and cytotoxity were observed. Conclusions： The heterologous deproteinized bone has good biological safety and meets all the demands of scaffold material for tissue engineering.

Paclitaxel formulation with stable sustained-release behavior and its biological safety evaluation

Biological safety and stable sustained-release of the drug are two crucial issues involved in the formulation of paclitaxel.Focusing on these issues, by using the FDA approved polylactide as carrier material, soybean lecithin as surfactant and maltodextrin as thickener, paclitaxel loaded PLA microspheres were simply prepared by solvent evaporation, thus guaranteeing the biological safety. The introduction of maltodextrin as a thickener aided to a stable sustained-release of paclitaxel. Surface morphology, particle size, drug loading rate, encapsulation efficiency and in vitro drug release behavior were investigated.Biological safety evaluations such as acute toxicity, allergies, hemolysis, skin stimulation and genotoxicity test were also carried out. Results showed that the obtained microspheres were biocompatible and could release paclitaxel at a desirable constant rate.Therefore, the simply prepared paclitaxel formulation with good biological safety and desirable release behavior exhibited great potential of local injection of paclitaxel for the clinical use in the future.

Genomovars of Burkholderia cepacia Complex from Rice Rhizosphere and Clinic in China

Burkholderia cepacia is regarded as a genetically distinct but phenotypically similar bacteria group referring to Burkholderia cepacia complex （Bcc）, which is found not only in clinic but also in rice growing environment. It is very important in microbial safety of rice for us to understand the genomovar status of Bcc. Genomovar analysis was performed among 87 Bcc isolates by means of Hae Ⅲ-recA RFLP assays and species-specific PCR tests. Three genomovars were found from the rice rhizosphere including Ⅰ, ⅢB and V, and genomovar V was predominant. Genomovars Ⅰ, ⅢA and ⅢB existed in the clinical samples, and genomovar ⅢA was the most popular. It showed that genomovar composition was different between the Bcc strains from the rice rhizosphere and clinical environment. Simultaneously, the results revealed the genetic diversity of Bcc strains from the rice rhizosphere, and genomovar Ⅲ referred as virulent species in clinic also existed in the rice rhizosphere.

Development of a large-scale isolation chamber system for the safe and humane care of medium-sized laboratory animals harboring infectious diseases

The close phylogenetic relationship between humans and non-human primates makes non-human primates an irreplaceable model for the study of human infectious diseases.In this study,we describe the development of a large-scale automatic multi-functional isolation chamber for use with medium-sized laboratory animals carrying infectious diseases.The isolation chamber,including the transfer chain,disinfection chain,negative air pressure isolation system,animal welfare system,and the automated system,is designed to meet all biological safety standards.To create an internal chamber environment that is completely isolated from the exterior,variable frequency drive blowers are used in the air-intake and air-exhaust system,precisely controlling the filtered air flow and providing an air-barrier protection.A double door transfer port is used to transfer material between the interior of the isolation chamber and the outside.A peracetic acid sterilizer and its associated pipeline allow for complete disinfection of the isolation chamber.All of the isolation chamber parameters can be automatically controlled by a programmable computerized menu,allowing for work with different animals in different-sized cages depending on the research project.The large-scale multi-functional isolation chamber provides a useful and safe system for working with infectious medium-sized laboratory animals in high-level bio-safety laboratories.

Biosafety and biobanking: Current understanding and knowledge gaps

Infectious disease outbreaks,such as'Coronavirus disease 20190(COVID-19),can constitute major global health threats with far-reaching consequences.As outbreaks develop,the international scientific community must provide high-quality scientific research-ready biological samples to solve the existing clinical and epidemiological questions to better combat the pandemic.Such examples are provided by dedicated biobank facilities,the latter collecting increasingly high volumes of biological samples.However,the more significant concentrations of infectious or potentially infectious biological materials can create a safety risk.The current short report describes the first attempt to identify the published scientific works on biobanking and safety.Three broad thematic areas have been identified:the physical security relevant to staff and sample integrity,the data safety aspects,and the governance parameters relating to the previous two.While the current publications reflect a broad alignment with existing standards and best practices in the biobanking field,they also demonstrate an opportunity for further in-depth work on this field in the post-COVID-19 era.

The role of leaders in laboratory safety: With an example from industry

Infectious disease research,like any scientific enterprise,is dependent on technology,subject matter experts,hard work…and engaged leadership.The pace of progress in research and development of vaccines,drugs,diagnostics or foundational knowledge is always more rapid when laboratory organizational cultures are collaborative and communication is open.Relationships of trust between individual scientists and with their leaders in an organization further fuel productivity.Laboratory safety is sometimes seen as just another administrative function,but that is far from the case.A focus on safety in an infectious disease laboratory not only protects the staff and the community around the lab;it also contributes to a healthy and vibrant organizational culture and even enhances productivity.

Surface charge-convertible quaternary ammonium salt-based micelles for in vivo infection therapy

Quaternary ammonium salts(QASs) are excellent candidates for treating stubborn bacterial infections caused by biofilms due to their high sterilization efficiency and potential inhibition of the development of drug resistance.However,the inherent toxicity of QASs,including cytotoxicity,protein absorption and hemolysis,severely limits their applications in vivo.Herein,a charge-co nvertible quaternary ammonium salt-based micelle(QAS-SL@CM) was constructed by co-assembly of two amphiphiles with opposite charges and shell cross-linking strategy.The toxicity of the QAS-SL@CM could be greatly reduced towa rds human cells contrast to the corresponding QASs.By response to the acidic environment at infection sites,the surface charge of QAS-SL@CM could be immediately changed to positive and then target to negatively charged bacteria.Furthermo re,β-thiopropionate bonds on QAS-SL@CM could also be disintegrated under acid environment to release QASs to kill bacteria.Importantly,the QAS-SL@CM showed significant therapeutic effect in mice subcutaneous abscesses models without interference with normal cells.Therefore,a surface adaptive micelle constructed by charge-convertible strategy has been developed to ove rcome the cytotoxicity of QAS s,and could intelligently respond to the microenvironment of infected wound for in vivo infection therapy,which shows promising application in clinic.