Comparison of chitosan and SLN nano-delivery systems for antibacterial effect of tea tree (Melaleuca alternifolia) oil against P. aeruginosa and S. aureus.

Treatment of wounds is challenging due to bacterial infections, including Staphylococcus aureus and Pseudomonas aeruginosa. Using the merits of alternative antimicrobials like tea tree oil (TTO) and nanotechnology, they can be helpful in combatting bacterial infections. Solid lipid nanoparticle (SLN) and chitosan (CS) nanoparticles show great potential as carriers for enhancing the stability and therapeutic benefits of oils. The aim of this study is to compare the influence of nanocarriers in enhancing the antibacterial effects of TTO. The study evaluates the physicochemical and antibacterial properties of TTO-SLN and TTO-CS against P. aeruginosa and S. aureus. The TTO-SLN nanoparticles showed a clear round shape with the average diameter size of 477 nm, while the TTO-CS nanoparticles illustrated very homogeneous morphology with 144 nm size. The encapsulation efficiency for TTO-CS and TTO-SLN was ∼88.3% and 73.5%, respectively. Minimum inhibitory concentration against S. aureus and P. aeruginosa for TTO-CS, TTO-SLN, and pure TTO were 35 and 45 µg ml-1, 130 and 170 µg ml-1, and 380 and 410 µg ml-1, respectively. Since TTO-CS revealed an impressively higher antimicrobial effects in comparison with TTO-SLN and TTO alone, it can be considered as a nanocarrier that produces the same antimicrobial effects with lower required amounts of the active substance.

Formulation of Cinnamon (Cinnamomum verum) oil loaded solid lipid nanoparticles and evaluation of its antibacterial activity against Multi-drug Resistant Escherichia coli.

Today, the increment in microbial resistance has guided the researches focus into new antimicrobial compounds or transmission systems. Escherichia coli (E. coli) is an opportunistic pathogen, producing a biofilm responsible for a wide range of nosocomial infections which are often difficult to eradicate with available antibiotics. On the other hand, Cinnamomum verum (cinnamon oil) (CO) is widely used as a natural antibacterial agent and Solid lipid nanoparticles (SLNs) are promising carriers for antibacterial compounds due to their lipophilic nature and ease of transmission through the bacterial cell wall. In this study, nanoparticles containing cinnamon oil (CO-SLN) were prepared by dual emulsion method and evaluated in terms of particle size, shape, entrapment efficiency (EE), transmission electron microscopy (TEM), oil release kinetics, and cell compatibility. The antibacterial activity of CO-SLN and CO against 10 drug-resistant E. coli strains was investigated. The anti-biofilm activity of CO-SLN on the selected pathogen was also investigated. Nanoparticles with an average size of 337.6 nm, and zeta potential of -26.6 mV were fabricated and their round shape was confirmed by TEM images. The antibacterial effects of CO-SLN and CO were reported with MIC Value of 60-75 µg/mL and 155-165 µg/mL and MBC value of 220-235 µg/ml and 540-560 µg/ml, respectively. On the other hand, CO-SLN with 1/2 MIC concentration had the greatest inhibition of biofilm formation in 24 h of incubation (55.25%). The data presented indicate that the MIC of CO-SLN has significantly reduced and it seems that SLN has facilitated and promoted CO transmission through the cell membrane.

Prognosis of heart transplant patients in Mashhad University of Medical Sciences.

INTRODUCTION: Heart transplant is the ultimate treatment for patients with end-stage heart failure. AIM: To assess 50 heart transplant patients for underlying diseases, transplantation outcome and mortality rate during a 5-year follow-up program. MATERIAL AND METHODS: Fifty heart transplant patients who underwent heart transplantation from 2012 to 2017 were assessed for underlying diseases, organ rejection, duration of hospitalization, extubation time, cardiac output and survival. Biopsy samples were obtained after surgery for evaluation of rejection. RESULTS: Dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) were the most common underlying diseases with prevalence of 56% and 12%, respectively. Significant improvement in ejection fraction was observed following heart transplant. Minimum and maximum extubation and hospitalization times were 3-408 hours and 1-51 days, respectively. Organ rejection evaluation 10 days after heart transplantation revealed that 50% of patients did not show any rejection while 10% had severe rejection. At 30 days post-operatively the number of patients with grade III rejection decreased to 2% while 56% of patients had no sign of rejection. The 5-year survival rate was 66% while infection and arrhythmia were the most common causes of death. CONCLUSIONS: DCM and ICM are considered the most prevalent underlying diseases in heart transplant candidates. Ejection fraction reached normal ranges following transplant, which provides good quality of life. Low incidence of severe acute rejection demonstrates the effectiveness of our immunosuppressive therapy. In the cases of increased rejection, the patient's immunosuppressive regimen was re-assessed accordingly.