Conventional vs PEGylated loaded liposomal formulations by microfluidics for delivering hydrophilic chemotherapy

Developing drug delivery systems (DDSs) is one of the approaches used to improve cancer treatment, with the main goal of loading cancer drugs into a carrier targeting a specific organ and avoiding the distribution to healthy tissues. Nanoparticles (NPs) have been shown to be one of the optimum carriers that can be used as DDSs. Lipid-based NPs, such as liposomes, have been investigated in the current study due to their low toxicity and ability to carry hydrophilic and hydrophobic molecules. In the current studies, conventional liposomes composed of DPPC, and cholesterol and PEGylated liposomes composed of DPPC, cholesterol, and DSPE-PEG2000 are manufactured and loaded with Carboplatin. The study focused on investigating and comparing the impact of modifying the carboplatin-loaded liposomes with different concentrations of DSPE-PEG2000 on the NP diameter, polydispersity, ζ-potential, encapsulation efficiency (EE%), and drug release. The hydrodynamic microfluidic system was used to investigate any possible improvement in the EE% over other conventional methods. The results showed the microfluidic system's promising effect in enhancing the EE% of the Carboplatin. Moreover, the results showed a smaller diameter and higher stability of the PEGylated liposome. However, conventional liposomes represent better homogeneity and higher encapsulation efficiency for hydrophilic molecules.

Synthesis and Characterization of Paclitaxel-Loaded PEGylated Liposomes by the Microfluidics Method

For cancer therapy, paclitaxel (PX) possesses several limitations, including limited solubility and untargeted effects. Loading PX into nanoliposomes to enhance PX solubility and target their delivery as a drug delivery system has the potential to overcome these limitations. Over the other conventional method to prepare liposomes, a microfluidic system is used to formulate PX-loaded PEGylated liposomes. The impact of changing the flow rate ratio (FRR) between the aqueous and lipid phases on the particle size and polydispersity index (PDI) is investigated. Moreover, the effect of changing the polyethylene glycol (PEG) lipid ratio on the particle size, PDI, stability, encapsulation efficiency % (EE %), and release profile is studied. The physicochemical characteristics of the obtained formulation were analyzed by dynamic light scattering, FTIR spectroscopy, and AFM. This work aims to use microfluidic technology to produce PEGylated PX-loaded liposomes with a diameter of <200 nm, low PDI < 0.25 high homogeneity, and viable 28 day stability. The results show a significant impact of FRR and PEG lipid ratio on the empty liposomes' physicochemical characteristics. Among the prepared formulations, two formulations produce size-controlled, low PDI, and stable liposomes, which make them preferable for PX encapsulation. The average EE % was >90% for both formulations, and the variation in the PEG lipid ratio affected the EE % slightly; a high packing for PX was reported at different drug concentrations. A variation in the release profiles was notified for the different PEG lipid ratios.

Nonlinear shear wave interaction at a frictional interface: energy dissipation and generation of harmonics

Analytical and numerical modeling of the nonlinear interaction of shear wave with a frictional interface is presented. The system studied is composed of two homogeneous and isotropic elastic solids, brought into frictional contact by remote normal compression. A shear wave, either time harmonic or a narrow band pulse, is incident normal to the interface and propagates through the contact. Two friction laws are considered and the influence on interface behavior is investigated: Coulomb's law with a constant friction coefficient and a slip-weakening friction law which involves static and dynamic friction coefficients. The relationship between the nonlinear harmonics and the dissipated energy, and the dependence on the contact dynamics (friction law, sliding, and tangential stress) and on the normal contact stress are examined in detail. The analytical and numerical results indicate universal type laws for the amplitude of the higher harmonics and for the dissipated energy, properly non-dimensionalized in terms of the pre-stress, the friction coefficient and the incident amplitude. The results suggest that measurements of higher harmonics can be used to quantify friction and dissipation effects of a sliding interface.

[Pyelo-ureteral junction syndrome in horse-shoe kidney. Report of 13 cases]

The pelviureteral junction upon a horse shoe kidney remains a frequent congenital malformation. The authors report 13 cases collected during a period of 16 years and treated surgically. The review of literature permits to discuss the different therapeutic means.

[Emphysematous pyelonephritis: review of the literature concerning a case report]

Emphysematous pyelonephritis is defined as the presence of gas-producing bacteria in the kidney and in peri-nephretic areas. Even if it is rare, the mortality rate of this affection is between 50% and 90%. The E. coli is responsible in 60% of the cases. We report a case of a 50 years old male patient, with under diagnosed diabetics, how is admitted with pains in the left flank, fever, troubled urine, hematuria and worsening of general state. The diagnostic of emphysematous pyelonephritis was confirmed by CT Scan. In spite of adapted antibiotherapy to the renal function, insulinotherapy and correction of hydro-electrolytic troubles, the patient died with septic shock associated to digestive bleeding. Based on this case and a review of the literature, the authors describe the different features of this disease. Only an urgent nephrectomy after a short reanimation can improve the prognostic.

[Tuberculosis of the hip: diagnostic problems. Apropos of 44 cases]

Diagnostic difficulties in 44 cases of tuberculosis of hip are emphasized and the serious nature of sequelae stressed. A definite diagnosis (cytology positive for Kochs bacillus, positive biopsy) was possible in only 18 cases, presumption of the nature of the affection in the other cases depending on clinical, radiologic and biologic arguments and failure to respond to immobilization one month.

Nitrogen mustard therapy in idiopathic nephrotic syndrome of childhood

The effects of intravenous Nitrogen Mustard (NM), given with a total cumulative dose of 0.8 mg/kg BW, were studied in 60 children with idiopathic nephrotic syndrome (INS). Thirty patients were frequent relapser with corticosteroid dependence. In this group the actuarial remission rate was 43, 30 and 15% after 1, 2 and 3 years respectively. The relapse rate per year was decreased from 2.76 +/- 1.56 to 0.88 +/- 0.79 after NM. Ten of the 17 patients showing a partial response to steroids went into complete remission after NM but 6 of them relapsed. Of the 13 patients who did not respond to steroids only 3 went into remission for a short time. Vomiting and leukopenia were noted in one third of cases. The data indicate that NM may improve the course of corticosteroid dependent INS, being less effective in partial responders and probably without effect in non responders.