scholarly journals Antimicrobial Peptides-Loaded Hydroxyapatite Microsphere With Different Hierarchical Structures for Enhanced Drug Loading, Sustained Release and Antibacterial Activity

2021 ◽  
Vol 9 ◽  
Author(s):  
Dandan Hong ◽  
Jingjing Wu ◽  
Xuemin Xiao ◽  
Xueyang Li ◽  
Dong Xu ◽  
...  

Antimicrobial peptides (AMPs) have great potential for clinical treatment of bacterial infection due to the broad-spectrum and highly effective antibacterial activity. However, the easy degradation and inactivation in vivo has been a major obstacle for their application and an effective delivery system is demanding. The surface physicochemical properties of the carrier, including surface potential, surface polarity, pore structure and morphology, have exerted great effects on the adsorption and release behavior of AMPs. This study investigated the influence of micro/nano carriers with different hierarchical structures on the loading, release and biological behavior of AMPs. Three types of AMPs-loaded hydroxyapatite microspheres (HA/AMPs MSs) with different hierarchical structures (needle-like, rod-like, and flake-like) were developed, which was investigated by the surface morphology, chemical composition and surface potential in detail. The different hierarchical structures of hydroxyapatite microspheres (HA MSs) had noticeable impact on the loading and release behavior of AMPs, and the flake-like HA MSs with hierarchical structure showed the highest loading efficiency and long-lasting release over 9 days. Meanwhile, the stability of AMPs released from HA MSs was effectively maintained. Moreover, the antibacterial test indicated that the flake-like HA/AMPs MSs showed more sustained antibacterial properties among three composites. In view of the excellent biocompatibility and osteogenic property, high loading efficiency and the long-term release properties of HA MSs with hierarchical structure, the HA/AMPs MSs have a great potential in bone tissue engineering.

2021 ◽  
Vol 8 ◽  
Author(s):  
Qi Liu ◽  
Wen-Chong Ouyang ◽  
Xiu-Hong Zhou ◽  
Tao Jin ◽  
Zheng-Wei Wu

In this study, nanofibers with different ratios of poly(vinyl alcohol) and chitosan incorporated with moxifloxacin hydrochloride (MH/PVA/CS) were fabricated through the blending electrospinning, and the morphological features were tested using scanning electron microscopy (SEM). Further characterization of the new nanofiber was accomplished by Thermogravimetric analysis (TG), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Antibacterial activity of the MH-loaded nanofibers at different drug loading were tested and compared with the blank group. Experimental results show that the MH/PVA/CS nanofibers exhibited the good antibacterial properties against Staphylococcus aureus and Pseudomonas aeruginosa due to the MH incorporation. Compared with blank nanofibers, MH/PVA/CS nanofibers have significantly better antibacterial properties, and different proportions of PVA and CS have a certain effect on the antibacterial activity of nanofibers. The conclusions in this paper show that MH/PVA/CS composite nanofibers may have great potential in antibacterial materials.


2019 ◽  
Vol 25 (34) ◽  
pp. 3692-3701 ◽  
Author(s):  
Hanif Ullah ◽  
Munair Badshah ◽  
Alexandra Correia ◽  
Fazli Wahid ◽  
Hélder A. Santos ◽  
...  

Background: Bacterial cellulose (BC) has recently attained greater interest in various research fields, including drug delivery for biomedical applications. BC has been studied in the field of drug delivery, such as tablet coating, controlled release systems and prodrug design. Objective: In the current work, we tested the feasibility of BC as a drug carrier in microparticulate form for potential pharmaceutical and biomedical applications. Method : For this purpose, drug-loaded BC microparticles were prepared by simple grinding and injection moulding method through regeneration. Model drugs, i.e., cloxacillin (CLX) and cefuroxime (CEF) sodium salts were loaded in these microparticles to assess their drug loading and release properties. The prepared microparticles were evaluated in terms of particle shapes, drug loading efficiency, physical state of the loaded drug, drug release behaviour and antibacterial properties. Results: The BC microparticles were converted to partially amorphous state after regeneration. Moreover, the loaded drug was transformed into the amorphous state. The results of scanning electron microscopy (SEM) showed that microparticles had almost spherical shape with a size of ca. 350-400 μm. The microparticles treated with higher drug concentration (3%) exhibited higher drug loading. Keeping drug concertation constant, i.e., 1%, the regenerated BC (RBC) microparticles showed higher drug loading (i.e., 37.57±0.22% for CEF and 33.36±3.03% for CLX) as compared to as-synthesized BC (ABC) microparticles (i.e., 9.46±1.30% for CEF and 9.84±1.26% for CLX). All formulations showed immediate drug release, wherein more than 85% drug was released in the initial 30 min. Moreover, such microparticles exhibited good antibacterial activity with larger zones of inhibition for drug loaded RBC microparticles as compared to corresponding ABC microparticles. Conclusion : Drug loaded BC microparticles with immediate release behaviour and antibacterial activity were fabricated. Such functionalized microparticles may find potential biomedical and pharmaceutical applications.


2018 ◽  
Vol 89 (17) ◽  
pp. 3506-3518 ◽  
Author(s):  
Jin Jeong ◽  
Seungsin Lee

Coptidis Rhizoma is a medicinal plant that is well known for its high antibacterial activity against various pathogens and its anti-inflammatory, antioxidant, and hemostatic effects. Here, nanofibrous membranes containing 10, 20, and 30 wt% of Coptidis Rhizoma extracts were fabricated by electrospinning using poly(vinyl alcohol) as the drug carrier and thermally treated to increase their aqueous stability. The antibacterial properties and release characteristics of Coptidis Rhizoma nanofibrous membranes were investigated. Coptidis Rhizoma-loaded nanocomposite fibers exhibited a high drug-loading efficiency ranging from 92% to 97%. The release profile from the nanofibrous membranes of Coptidis Rhizoma showed an initial fast release followed by a gradual release for 48 h. High antibacterial activity of the Coptidis Rhizoma-loaded nanofibrous membranes was exhibited against both Staphylococcus aureus and Staphylococcus epidermidis. These results demonstrate that poly(vinyl alcohol) nanofibrous membranes containing Coptidis Rhizoma extracts have considerable potential to be effective antimicrobial wound dressings based on natural substances.


2021 ◽  
Vol 23 (05) ◽  
pp. 384-391
Author(s):  
Abhijith Ram Narayan V ◽  
◽  
Shethal Anilkumar ◽  
Sanjay Prasad S ◽  
◽  
...  

Wound infection is a major complication in healing of chronic wounds. Diabetic wounds are highly prone to wound infection and development of drug resistance among pathogens has created a necessity for development of new antimicrobials for treatment of such wound infections. Antimicrobial peptides (AMP) are found to be potent source showing promising antimicrobial action. Therefore the present study focuses on extraction of AMP from Catla catla skin using two different solvents and determining antibacterial activity against wound pathogens. Specimens from wound were collected using sterile swabs and streaked on nutrient agar. Then the colonies were subjected to gram staining and series of biochemical tests for identification. Live fish of Catla catla weighing 470gm was collected, homogenized in two different solvents (Ethanol and water). Antibacterial activity of the crude extracts of AMP was evaluated by using well diffusion method. Based on the colony morphology and biochemical tests the pathogens were found to be Staphylococcus aureus and Pseudomonas aeruginosa. The wound pathogens isolated were also found to be a biofilm producer. Antibacterial analysis showed ethanolic extract had higher inhibition than aqueous extracts. Therefore the extracted AMP can be used for development of novel antibacterial drugs for treatment of drug resistant bacterial infections.


2014 ◽  
Vol 9 (4) ◽  
pp. 155892501400900 ◽  
Author(s):  
Hossein Barani ◽  
Majid Montazer ◽  
Nasrin Samadi ◽  
Tayebeh Toliyat ◽  
Mohsen Khorashadi Zadeh ◽  
...  

Silver nanoparticles (AgNPs) were synthesized with lecithin through a simple chemical reduction method. The prepared AgNPs/lecithin was then loaded into the wool fabric by exhaustion and pad-dry-cure methods. The surface morphology of the loaded wool fabrics was characterized by low-voltage scanning electron microscopy, and the loading efficiency was determined by inductively coupled plasma optical emission spectrometry. Further, the effect of the different lecithin concentrations was examined on the antibacterial activity, cytotoxicity, and color of the loaded wool fabrics. The loaded fabric with AgNPs at a higher lecithin ratio presented higher antibacterial activity due to the higher loading efficiency and smaller nanoparticle size. Also, the morphology of the fibroblast cells in cytotoxicity test was not changed in presence of extracted solution from the treated wool fabrics with different lecithin concentration.


Author(s):  
E. Baer

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.


2019 ◽  
Author(s):  
Michiru Makuuchi

Symbolic behaviours such as language, music, drawing, dance, etc. are unique to humans and are found universally in every culture on earth1. These behaviours operate in different cognitive domains, but they are commonly characterised as linear sequences of symbols2,3. One of the most prominent features of language is hierarchical structure4, which is also found in music5,6 and mathematics7. Current research attempts to address whether hierarchical structure exists in drawing. When we draw complex objects, such as a face, we draw part by part in a hierarchical manner guided by visual semantic knowledge8. More specifically, we predicted how hierarchical structure emerges in drawing as follows. Although the drawing order of the constituent parts composing the target object is different amongst individuals, some parts will be drawn in succession consistently, thereby forming chunks. These chunks of parts would then be further integrated with other chunks into superordinate chunks, while showing differential affinity amongst chunks. The integration of chunks to an even higher chunk level repeats until finally reaching the full object. We analysed the order of drawing strokes of twenty-two complex objects by twenty-five young healthy adult participants with a cluster analysis9 and demonstrated reasonable hierarchical structures. The results suggest that drawing involves a linear production of symbols with a hierarchical structure. From an evolutionary point of view, we argue that ancient engravings and paintings manifest Homo sapiens’ capability for hierarchical symbolic cognition.


2020 ◽  
Vol 24 (8) ◽  
pp. 817-854
Author(s):  
Anil Kumar ◽  
Nishtha Saxena ◽  
Arti Mehrotra ◽  
Nivedita Srivastava

Quinolone derivatives have attracted considerable attention due to their medicinal properties. This review covers many synthetic routes of quinolones preparation with their antibacterial properties. Detailed study with structure-activity relationship among quinolone derivatives will be helpful in designing new drugs in this field.


Sign in / Sign up

Export Citation Format

Share Document