The new antibiotic vector brings a turnaround to patients with chronic myelitis

(left) to guide Xu Zhengjiang's assistant researchers in the preparation of composite nano-carriers.
Chronic myelitis is a chronic inflammatory process caused by bacteria and accompanied by bone damage, which can be confined to a single type of bone tissue, but also affect bone marrow, bone, bone membrane and surrounding soft tissue.
because of repeated episodes of inflammation, the infection is not healing, chronic myelitis will have a greater impact on limb function, such as muscle atrophy, pathological fractures, limb shortness or deformity. If the disease is close to the joint, it can also cause joint contractions, stiffness and difficulty in activity.
refore, once the formation of chronic myelitis, often need multiple treatment, its long course of disease, difficult to cure, to the patient brought great physical and mental pain, but also to the patient's family and society caused a heavy burden., the clinical treatment of chronic myelitis is usually treated with surgical treatment combined with systemic/local antibiotics.
in the case of antibiotic therapy, the first step is to select an appropriate bacterially sensitive antibiotic, and second, antibiotics need to be maintained at sufficient antibacterial concentration serum levels throughout the treatment to achieve therapeutic results.
other words, the treatment of chronic myelitis takes into account not only the type of drug, but also the method of transporting the drug to the infected site.
because chronic myelitis patients tend to have poor blood flow, even the use of antibiotics throughout the body can not form enough effective blood concentration in the patient, resulting in poor treatment. Local medication can form enough concentration of the drug in the patient to kill the bacteria in the patient.
, however, most of the antibiotic vectors commonly used in clinical practice are bone cement or calcium sulfate, and their compound with antibiotics is a simple physical mix, sometimes there is a problem of uneven mixing. Moreover, when these vectors release antibiotics, there is often a sudden release effect, which can not achieve long-term load and effective slow release of antibiotics.
note that local high concentrations of antibiotics, although effective in controlling infection, can have significant toxic side effects on surrounding tissues and even interfere with the formation of new bones. Therefore, the local use of antibiotics for the long-term treatment of chronic myelitis is not ideal.
recently, researchers from the
Shenzhen Institute of Advanced Technology and the First Affiliated Hospital of the Naval Medical University collaborated to develop a new type of antibiotic nanotranscer - the introduction of hydroxyphosphate nanoparticles encased in place with interforous bioactive glass (MBG) A large proportion of bioactive Si ions can not only relieve the toxic side effects of antibiotics on cells and inhibit bone production in the body, thus improving bone regeneration at the site of myelitis infection, providing new ideas for the treatment of chronic myelitis, but also promising to broaden the application of inororated ions in the biomedical field. The findings were published online in the Journal of Chemical Engineering." ideal antibiotic vector should have a dual function of controlling/continuous release of antibiotics to eliminate infection, while also having high bone-induced activity to promote bone regeneration.
Wang Cheng, an associate researcher at the Degenerative Research Center of Human Tissue and Organs at the Institute of Advanced Technology in Shenzhen, said in an interview with China Science Daily that the current research and development of new antibiotic vectors is mainly focused on optimizing their load and release characteristics, while largely ignoring the issue of "how to counteract the negative effects of high concentrations of antibiotics on bone regeneration".
to solve this problem, Wang Cheng's research team joined forces with Xu Shugui of the War Trauma Center of the First Affiliated Hospital of naval medical university to explore a new antibiotic vector with dual functions.
in previous studies, the Kingdom team found that MBG load recombination of human bone morphology protein-2 (rhBMP-2) can achieve the sustained and slow release of growth factors and promote the regeneration of the internal and outer bones. At the same time, the team also used plasma spraying technology to prepare a Si coating on the surface of the titanium alloy, which showed that the coating not only helped the cell bone differentiation, but also promoted bone regeneration in the body.
MBG also has a unique advantage in bone-forming and drug-carrying. MBG has an orderly nano-hole structure and a large surface area and hole volume, which provides good conditions for the loading of pharmaceutical molecules and is widely used in drug delivery.
compared to ordinary biological glass, MBG inorder particles have higher drug loading and slow release ability, not only that, but also has a very strong ability to induce the formation of urn-like phosphorite. "MBG releases bioactive Si ions, which have been shown to promote cell differentiation and induce bone regeneration." Kingdom Cheng said.
hydroxyphosphate (HAp) is the main inorges in the bone, and there have been many studies to use its load antibiotics to treat myelitis. However, in Wang Cheng's view, the use of hydroxyurea as a carrier, there are poor drug loading and drug sudden release and other deficiencies, affecting its effect after loading drugs.
Although many researchers have prepared Si-HAp by replacing doping, the proportion of Si doping in this way is limited and does not improve the surface area and hole volume of HAp, which is generally available for drug release and bone effect.
After continuous research and exploration, combined with MMG's advantages in bone formation and drug delivery, the team wrapped MBG in place on the surface of hydroxyurea, gave it a mesoporoid structure, and introduced a larger proportion of bioactive Si ions, forming a new antibiotic nanotranscer.
" this new antibiotic nano carrier to achieve local delivery of antibiotics can not only avoid the side effects of systemic antibiotic treatment, but also can achieve the continued high concentration delivery of antibiotics at the site of infection, can more effectively treat chronic myelitis. Kingdom Cheng said. the ninth floor of the earth, starting from the soft soil. Scientific innovation has never happened overnight. In recent years, Wang Cheng and Xu Shugui led the research team to carry out a series of fruitful basic research and technical research, which laid the foundation for today's breakthrough.
Kingdom Cheng research team relying on the
Shenzhen Institute of Advanced Technology Medical Research Center for human tissue and organ descess, long-term engaged in dental implant surface engineering technology development and biological materials - tissue interface control research, now has a number of metal implant surface biosulation and bone repair materials patented technology.
has been dedicated to myelitis, bone-related clinical treatment and basic research, as well as the basic research and development of new bone repair materials and clinical transformation, published in internationally renowned journals a number of research papers.
to accumulate, only for thick accumulation of thin hair. "The development of biomaterials needs to be clinically oriented, and through long-term and frequent academic exchanges, the two teams ensure that the development of materials is based on a full understanding of the current problems in the treatment of clinical myelitis. In this collaboration, I fully appreciate the inclusion, trust and effective collaboration of team members. Kingdom Cheng said.
In the course of the implementation of the project, the main implementers of the experiment
Xu Zhengjiang, an assistant researcher at the Shenzhen Institute of Advanced Technology, and Dr. Xia Wei, a first affiliated hospital of the Naval Medical University, often exchanged views on the details of the experiment.
the results of the study is exciting, but the taste of the period can only be experienced by those who have experienced it. So far Xu Zhengjiang also clearly remembers that in the preparation process of MBG/HAp composite carrier, he encountered MMG in the surface of HAp particles difficult to wrap and HAP easy to reunite and other issues.
in order to solve the above problems, he tried different preparation methods and optimized the series preparation parameters. On the first attempt, he mixed the MBG sol with the dried HAp nano-powder with a solid solution, which was then steamed and sintered to prepare the MBG/HAp composite carrier. Scanned and viewed by an electric mirror, the HAp grain table has very little MBG covered with bread and cannot be evenly wrapped. The results left Xu Zhengjiang bewildered.
Later, after a period of trial and error, he adopted an improved approach, which was to precipitate the legally prepared HAp without drying direct ultrasonic dispersion, and then added a fully dispersed HAp during the MBG synthesis process, the precursor hydrolysing process, to achieve in-place agglycation of MPG on the surface of the HAp, resulting in the successful obtain of HAp particles evenly wrapped by the MMG.
has made a breakthrough in research, but the research team has not stopped. "In this study, we have initially confirmed that Si ions are able to resist to some extent the toxic side effects of antibiotics on cells, but the mechanism of their action has not yet been clarified. In a follow-up study, the team will further develop the molecular mechanisms of Si ions to alleviate antibiotic side effects through molecular biology. In addition, we will evaluate Si ions' ability to resist the side effects of vancomycin on other types of cells, and we will also examine whether Si ions can alleviate the toxic side effects of other types of antibiotics on cells. "The kingdom is finally represented. (Source: China Science Journal, Weibo)
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