Investigation of Antibiotic Release from Bone Allograft in an Experiment on Rabbits

BACKGROUND: The treatment of chronic osteomyelitis, despite the use of new methods, is still an urgent problem. Local use of antibacterial drugs in combination with systemic antibiotic therapy has become popular in recent decades. Autologous bone grafts are considered ideal for bone defects filling. Different methods of allograft preparation may have differences in the rate and duration of antibiotic release. Moreover, it can affect the effectiveness of microbial agent eradication. The study analyzed the differences in the release of gentamicin from different types of allografts in dynamics and methods of preparation: «PerOssal» medium, whole bone allograft soaked in antibiotic, whole bone allograft, welded with an antibiotic, and perforated bone allograft soaked in an antibiotic solution. AIM: The objective of the study was to study the stability of antibiotic release and to determine the effectiveness of local transport systems. Evaluation of the difference in gentamicin release from different types of allografts in dynamics and methods of preparation had been realized: “PerOssal” medium, whole bone allograft soaked in antibiotic, whole bone allograft welded with an antibiotic, and perforated bone allograft, soaked in antibiotic solution. MATERIALS AND METHODS: The research was conducted between September 2020 and March 2021. The experiments were performed on 120 laboratory rabbits (weight – 3000–3500 g, age – 6–8 months), which were divided into four groups (30 animals in each group). Group 1 consisted of animals treated with “PerOssal.” The whole bone allograft soaked in an antibiotic was used in the treatment of animals of Group 2. The whole bone allograft, welded with an antibiotic, was used in the treatment of animals of Group 3. Perforated bone allograft soaked in an antibiotic was used in Group 4. Osteomyelitis of the proximal femur was formed in experimental animals. RESULTS AND DISCUSSION: Statistically insignificant decrease in the concentration of gentamicin was observed by the 7th day in all experimental groups. In rabbits whose bone defect was filled with a whole bone allograft welded with antibiotic and perforated bone allograft impregnated with an antibiotic (Groups 3 and 4), the most stable concentration of gentamicin was noted throughout the study period. Statistically significant differences were revealed between the experimental groups in relation to the dynamics of changes in the concentration of gentamicin in blood plasma. It was found that the group using the biodegradable material “PerOssal” on the 1st day showed a high concentration of the antibiotic in the blood plasma. However, by the 2nd day, a lower concentration of the antibiotic was recorded compared to all comparison groups of the bone allograft. CONCLUSIONS: The results of the analysis of the dynamics of gentamicin concentration may indicate significant differences between the methods of graft preparation, especially in the relationship with antibiotic release into the blood plasma. The most stable antibiotic concentration was registered in the groups of animals that underwent the filling of bone defect using a whole bone allograft welded with an antibiotic and a perforated bone allograft impregnated with antibiotic. A significant decrease of gentamicin concentration in the femur homogenate by the 7th day after transplantation was observed when using a whole bone allograft impregnated with an antibiotic. At the same time, a stable concentration of the antibiotic in the blood plasma was registered. The highest initial antibiotic concentration in the homogenate with a gradual decrease over 7 days was observed when using the antibiotic-impregnated biodegradable material “PerOssal.”

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Evaluation of a bone filler scaffold for local antibiotic delivery to prevent Staphylococcus aureus infection in a contaminated bone defect

Scientific Reports ◽

10.1038/s41598-021-89830-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Karen E. Beenken ◽

Mara J. Campbell ◽

Aura M. Ramirez ◽

Karrar Alghazali ◽

Christopher M. Walker ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Bone Defect ◽

Rabbit Model ◽

In Vivo Studies ◽

Bovine Bone ◽

Bone Filler ◽

Antibiotic Release ◽

Local Antibiotic ◽

Antibiotic Delivery

AbstractWe previously reported the development of an osteogenic bone filler scaffold consisting of degradable polyurethane, hydroxyapatite, and decellularized bovine bone particles. The current study was aimed at evaluating the use of this scaffold as a means of local antibiotic delivery to prevent infection in a bone defect contaminated with Staphylococcus aureus. We evaluated two scaffold formulations with the same component ratios but differing overall porosity and surface area. Studies with vancomycin, daptomycin, and gentamicin confirmed that antibiotic uptake was concentration dependent and that increased porosity correlated with increased uptake and prolonged antibiotic release. We also demonstrate that vancomycin can be passively loaded into either formulation in sufficient concentration to prevent infection in a rabbit model of a contaminated segmental bone defect. Moreover, even in those few cases in which complete eradication was not achieved, the number of viable bacteria in the bone was significantly reduced by treatment and there was no radiographic evidence of osteomyelitis. Radiographs and microcomputed tomography (µCT) analysis from the in vivo studies also suggested that the addition of vancomycin did not have any significant effect on the scaffold itself. These results demonstrate the potential utility of our bone regeneration scaffold for local antibiotic delivery to prevent infection in contaminated bone defects.

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Heparin-mediated antibiotic delivery from an electrochemically-aligned collagen sheet

Bio-Medical Materials and Engineering ◽

10.3233/bme-201133 ◽

2021 ◽

pp. 1-12

Author(s):

Olivia T. Cheng ◽

Andrew P. Stein ◽

Eric Babajanian ◽

Kathryn R. Hoppe ◽

Shawn Li ◽

...

Keyword(s):

High Performance ◽

Inhibitory Concentration ◽

Medical Implants ◽

Implantable Medical Devices ◽

Antibiotic Solution ◽

Inhibition Zones ◽

Antibiotic Release ◽

Local Antibiotic ◽

Antibiotic Delivery

BACKGROUND: Implantable medical devices and hardware are prolific in medicine, but hardware associated infections remain a major issue. OBJECTIVE: To develop and evaluate a novel, biologic antimicrobial coating for medical implants. METHODS: Electrochemically compacted collagen sheets with and without crosslinked heparin were synthesized per protocol developed by our group. Sheets were incubated in antibiotic solution (gentamicin or moxifloxacin) overnight, and in vitro activity was assessed with five-day diffusion assays against Pseudomonas aeruginosa. Antibiotic release overtime from gentamicin infused sheets was determined using in vitro elution and high performance liquid chromatography (HPLC). RESULTS: Collagen-heparin-antibiotic sheets demonstrated larger growth inhibition zones against P. aeruginosa compared to collagen-antibiotic alone sheets. This activity persisted for five days and was not impacted by rinsing sheets prior to evaluation. Rinsed collagen-antibiotic sheets did not show any inhibition zones. Elution of gentamicin from collagen-heparin-gentamicin sheets was slow and remained above the minimal inhibitory concentration for gentamicin sensitive organisms for 29 days. Conversely, collagen-gentamicin sheets eluted their antibiotic payload within 24 hours. Overall, heparin associated sheets demonstrated larger inhibition zones against P. aeruginosa and prolonged elution profile via HPLC. CONCLUSION: We developed a novel, local antibiotic delivery system that could be used to coat medical implants/hardware in the future and reduce post-operative infections.

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Air quality sensors in public transport stops and cross-system communication

Journal of Research and Innovation for Sustainable Society ◽

10.33727/jriss.2021.1.1:5-10 ◽

2021 ◽

Vol 3 (1) ◽

pp. 5-10

Author(s):

Dan-Marius Mustață

Keyword(s):

Air Quality ◽

Public Transport ◽

Traffic Management ◽

Transport Systems ◽

View Point ◽

System Communication ◽

Warning Messages ◽

Different Types ◽

Cross System ◽

State Of Art

The purpose of this article is to present a state of art implementation of air quality sensors in public transport stops. Effects on health due to different types of pollutants are summarized as well. Functional scope of the solutions, via warning messages displayed for passengers waiting at these stops, including a cross system communication between traffic management and public transport systems, are also focused. Analysis of existing sensor types from multiple view point including functions, types of measured pollutants, price ranges and comparisons are outlined.

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Globalization of the transport system of the agro-industrial complex in the conditions of modern society

E3S Web of Conferences ◽

10.1051/e3sconf/202017605020 ◽

2020 ◽

Vol 176 ◽

pp. 05020

Author(s):

M.A. Ananyev ◽

Zh.Yu Bakaeva ◽

O.L. Matveeva ◽

I.V. Steklova ◽

E.N. Shchegoleva

Keyword(s):

Transport System ◽

Modern Society ◽

Transport Systems ◽

Industrial Complex ◽

Structural Elements ◽

Economic Space ◽

Different Types ◽

Food Market ◽

Temporal And Spatial ◽

Favorable Conditions

The article deals with the problem of transportation of agricultural products. The main causes of problems in this area are identified. The mechanism of creating favorable conditions in the system of globalization relations of the modern economy is analyzed. The fundamental elements in the transport system are competition orientation and information ownership over a certain period of time. Globalization involves the integration of different types of transport systems at the sectoral characteristics. The purpose of the research is to study the essence, meaning and prospects of the concept of “economic transport space in the national food supply system" in the processes of food market globalization. The main indicators of the “economic space" are: first, to determine the parameters that characterize the economic transport space, and secondly, to determine the prospects for using its structural elements in the system of transport supply relations, depending on the temporal and spatial components in the modern sector of the economy to provide food for the needs of society.

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Bone Repair in Periodontal Defect Using a Composite of Allograft and Calcium Sulfate (DentoGen) and a Calcium Sulfate Barrier

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-10-00006.1 ◽

2011 ◽

Vol 37 (2) ◽

pp. 287-292 ◽

Cited By ~ 17

Author(s):

Ziv Mazor ◽

Sachin Mamidwar ◽

John L. Ricci ◽

Nick M. Tovar*

Keyword(s):

Connective Tissue ◽

Periodontal Disease ◽

Bone Defect ◽

Calcium Sulfate ◽

Bone Repair ◽

Bone Allograft ◽

Bone Defects ◽

Defect Analysis ◽

Freeze Dried ◽

Time Point

Abstract Deep bone defects are caused by the progression of periodontal disease, which breaks down bone and connective tissue that hold teeth in place. In this case, a 37-year-old male patient presented a deep bone defect with advanced periodontal disease around an upper canine. Medical-grade calcium sulfate was mixed with demineralized freeze-dried bone allograft and used to repair and regenerate the defect. Analysis of the radiographs at the 5-month time point showed the bone had completely regenerated.

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THE CONTENT OF SULFUR-CONTAINING AMINO ACIDS AND RELATED COMPOUNDS IN THE BLOOD PLASMA OF RATS WITH DIFFERENT TYPES OF ALCOHOL INTOXICATION

Journal of the Grodno State Medical University ◽

10.25298/2221-8785-2021-19-2-170-175 ◽

2021 ◽

Vol 19 (2) ◽

pp. 170-175

Author(s):

A. K. Semenchuk ◽

◽

V. V. Lelevich ◽

Keyword(s):

Amino Acids ◽

Blood Plasma ◽

Free Amino ◽

Alcohol Intoxication ◽

Chronic Alcohol ◽

Rat Blood ◽

Chronic Alcohol Intoxication ◽

Different Types ◽

Related Compounds ◽

Sulfur Containing

Background. Change of the content of sulfur-containing amino acids and their metabolites is one of the pathochemical mechanisms of alcohol intoxication. Purpose of the study. To study the effect of chronic and intermittent alcohol intoxication on the content of sulfurcontaining amino acids and related compounds in the rat blood plasma. Material and methods. Thirty white outbred rats weighing 180-220 g. The content of free amino acids and biogenic amines was determined by HPLC. Results. A 14-day chronic alcohol intoxication was accompanied by a significant decrease in the level of methionine and an increase in the level of homocysteine in the blood plasma. The concentration of glutathione increased by 5%. In the intermittent alcohol intoxication IAI-4 group, the homocysteine content also increased, as did the level of homoserine and cystathionine in the IAI-1 group. Conclusions. Сhronic and intermittent alcohol intoxications cause similar violations of the level of sulfur-containing amino acids and their metabolites in the rat blood plasma.

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The Small GTPase OsRac1 forms two distinct immune receptor complexes containing the PRR OsCERK1 and the NLR Pit

10.1101/2020.07.01.183301 ◽

2020 ◽

Author(s):

Akira Akamatsu ◽

Masayuki Fujiwara ◽

Satoshi Hamada ◽

Megumi Wakabayashi ◽

Ai Yao ◽

...

Keyword(s):

Plasma Membrane ◽

Protein Complex ◽

Small Gtpase ◽

Surface Pattern ◽

Transport Systems ◽

Large Protein ◽

Pathogen Invasion ◽

Receptor Complexes ◽

Immune Receptors ◽

Different Types

AbstractPlants employ two different types of immune receptors, cell surface pattern recognition receptors (PRRs) and intracellular nucleotide-binding and Leucine-rich repeat-containing proteins (NLRs), to cope with pathogen invasion. Both immune receptors often share similar downstream components and responses but it remains unknown whether a PRR and an NLR assemble into the same protein complex or two distinct receptor complexes. We have previously found that the small GTPase OsRac1 plays key roles in the signaling of OsCERK1, a PRR for fungal chitin, and of Pit, an NLR for rice blast fungus, and associates directly and indirectly with both of these immune receptors. In this study, using biochemical and bioimaging approaches, we reveal that OsRac1 formed two distinct receptor complexes with OsCERK1 and with Pit. Supporting this result, OsCERK1 and Pit utilized different transport systems for anchorage to the plasma membrane. Activation of OsCERK1 and Pit led to OsRac1 activation and, concomitantly, OsRac1 shifted from a small to a large protein complex fraction. We also found that the chaperone Hsp90 contributed to the proper transport of Pit to the plasma membrane and the immune induction of Pit. These findings illuminate how the PRR OsCERK1 and the NLR Pit orchestrate rice immunity through the small GTPase OsRac1.

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Current trends in the formation of international transport systems

E3S Web of Conferences ◽

10.1051/e3sconf/202017514014 ◽

2020 ◽

Vol 175 ◽

pp. 14014

Author(s):

Vera Baginova ◽

Andrey Zenkin ◽

Dmitriy Ushakov

Keyword(s):

Retrospective Analysis ◽

Transport System ◽

Economic Cooperation ◽

Transport Systems ◽

Economic Relations ◽

Current Trends ◽

Different Types ◽

International Transport ◽

Definition Of

The purpose of the study is to establish and formalize current trends in the construction and formation of international transport systems. In this regard, first of all, the definition of international transport systems is given. In modern conditions, the formation and development of national transport systems is largely determined by the focus on international transport and economic relations, and the possibility of attracting international transit cargo flows to the transport system of countries. In this paper, all systems of existing transport corridors, Euro-Asian transport directions, transport of regions of economic cooperation and existing agreements on international routes and lines on different types of transport are considered in the axiomatic of their classification as international transport systems. A retrospective analysis of the development of international transport systems, their transformation and conversion in the process of evolution is given. In conclusion, the paper provides recommendations on the need for further research related to the theoretical and conceptual justification of trends in the formation of international transport systems, the study of legal support for their functioning, modeling the interaction of different types of transport, the prospects for their development, the possible assessment of efficiency and other issues related to thisproblem.

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Different subcellular locations of secretome components of Gram-positive bacteria

Microbiology ◽

10.1099/mic.0.29113-0 ◽

2006 ◽

Vol 152 (10) ◽

pp. 2867-2874 ◽

Cited By ~ 31

Author(s):

Girbe Buist ◽

Anja N. J. A. Ridder ◽

Jan Kok ◽

Oscar P. Kuipers

Keyword(s):

Cell Wall ◽

Cytoplasmic Membrane ◽

Secretion System ◽

Transport Systems ◽

Cell Wall Synthesis ◽

Secretion Systems ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Different Types ◽

Folded Proteins

Gram-positive bacteria contain different types of secretion systems for the transport of proteins into or across the cytoplasmic membrane. Recent studies on subcellular localization of specific components of these secretion systems and their substrates have shown that they can be present at various locations in the cell. The translocons of the general Sec secretion system in the rod-shaped bacterium Bacillus subtilis have been shown to localize in spirals along the cytoplasmic membrane, whereas the translocons in the coccoid Streptococcus pyogenes are located in a microdomain near the septum. In both bacteria the Sec translocons appear to be located near the sites of cell wall synthesis. The Tat secretion system, which is used for the transport of folded proteins, probably localizes in the cytoplasmic membrane and at the cell poles of B. subtilis. In Lactococcus lactis the ABC transporter dedicated to the transport of a small antimicrobial peptide is distributed throughout the membrane. Possible mechanisms for maintaining the localization of these secretion machineries involve their interaction with proteins of the cytoskeleton or components of the cell wall synthesis machinery, or the presence of lipid subdomains surrounding the transport systems.

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Evaluation of incorporation of bone allograft at the site of implantation in various clinical conditions along with its complications

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20202681 ◽

2020 ◽

Vol 6 (4) ◽

pp. 760

Author(s):

Laxmi Narayan Jajoriya ◽

Sumit Sural

Keyword(s):

Bone Defect ◽

Elective Surgery ◽

Bone Allograft ◽

Control Policy ◽

Filling Defect ◽

Non Union ◽

Acetabular Bone Defect ◽

Hospital Infection Control ◽

Skeletal Defects ◽

Fresh Frozen

Background: Bone transplants have been used routinely in the present century for diverse purposes to unite fractures, fuse joints, and repair skeletal defects.Methods: Twelve patients with fracture, bone defect, deformity, difficulty in the fusion of bone, etc. were taken in the study for elective surgery with fresh frozen allograft in the orthopedics department with the incorporation of inclusion and exclusion criteria.Results: Out of 12 cases in this study, 7 cases were related to spinal fusion, 3 cases were of fractures with bone defects, 1 case of non-union neck femur fracture and 1 case was of revision hip arthroplasty with the acetabular bone defect. Seventy-five percent (9 patients) and 25% (3 patients) were graded fair and poor respectively in the preoperative phase. At 6 months, excellent results were obtained in 50% (6 patients), good in 25% (3 patients), fair in 25% (3 patients), while none were graded as poor in terms of clinical evaluation.Conclusions: Fresh frozen bone, a good source of abundant bone allograft, can be stored in -70° freezer for use in orthopedic surgery to fill any filling defect in the bone. Also, proper storage, better surgical technique, hospital infection control policy, antibiotic policy, preoperative use of antibiotics before surgery has a good clinical outcome.

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