Poloxamers for Surface Modification of Hydrophobic Drug Carriers and Their Effects on Drug Delivery

Tri-block copolymer poloxamers are successfully employed for reducing adsorption of proteinous molecules onto hydrophobic surfaces, which will protect them from quick engulfing by macrophages. For sustained systemic circulation of hydrophobic drug carriers, particle surfaces need suitable modification for avoiding phagocytosis and this can be successfully done by poloxamers. They can affect the drug release profile, which makes them a very promising agent for targeted delivery. This review discusses the structure, characteristics and advantages of poloxamers. Poloxamer adsorption onto hydrophobic surfaces and adlayer thickness, relative phagocytic uptake and drug release profiles of coated drug loaded particles have been described in detail

Estimated pulse wave velocity is associated with all-cause and cardio-cerebrovascular disease mortality in stroke population: Results from NHANES (2003–2014)

BackgroundArterial stiffness is a significant determinant and evaluation of cardio-cerebrovascular disease and all-cause mortality risk in the stroke population. Estimated pulse wave velocity (ePWV) is a well-established indirect measure of arterial stiffness. We examined the association of ePWV with all-cause and cardio-cerebrovascular disease (CCD) mortality in the stroke population in a large sample of US adults.MethodsThe study design was a prospective cohort study with data from the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2014, between the ages of 18–85 years, with follow-up through December 31, 2019. 1,316 individuals with stroke among 58,759 participants were identified and ultimately, 879 stroke patients were included in the analysis. ePWV was calculated from a regression equation using age and mean blood pressure according to the following formula: ePWV = 9.587 − (0.402 × age) + [4.560 × 0.001 × (age2)] − [2.621 × 0.00001 × (age2) × MBP] + (3.176 × 0.001 × age × MBP) − (1.832 × 0.01 × MBP). Survey-weighted Cox regression models were used to assess the association between ePWV and all-cause and CCD mortality risk.ResultsThe high ePWV level group had a higher increased risk of all-cause mortality and CCD mortality compared to the low ePWV level group after fully adjusting for covariates. With an increase in ePWV of 1 m/s, the risk of all-cause and CCD mortality increased by 44%–57% and 47%–72% respectively. ePWV levels were linearly correlated with the risk of all-cause mortality (P for nonlinear = 0.187). With each 1 m/s increase in ePWV, the risk of all-cause mortality increased by 44% (HR 1.44, 95% CI: 1.22–1.69; P < 0.001). When ePWV was <12.1 m/s, an increase in ePWV per 1 m/s was associated with a 119% (HR 2.19, 95% CI: 1.43–3.36; P < 0.001) increase in CCD mortality risk; when ePWV was ≥12.1 m/s, an increase in ePWV per 1 m/s was not associated with in CCD mortality risk.ConclusionePWV is an independent risk factor for all-cause and CCD mortality in stroke patients. Higher levels of ePWV are associated with higher all-cause mortality and CCD mortality in stroke patients

In vitro IFN-α release from IFN-α- and pegylated IFN-α-loaded poly(lactic-co-glycolic acid) and pegylated poly(lactic-co-glycolic acid) nanoparticles

Aim: Interferon alpha (IFN-α) controlled release of nanoparticles was investigated under in vitro conditions. Materials &amp; methods: IFN-α and pegylated IFN-α (PEG-IFN-α) were encapsulated by poly(lactic-co-glycolic acid) (PLGA) and pegylated PLGA (PEG-PLGA) copolymers using double emulsion solvent evaporation method. Results: The size of resulting four nanoparticles (IFN-α in poly(lactic-co-glycolic acids), IFN-α in poly(lactic-co-glycolic acid)-polyethylene glycol, PEG-IFN-α in poly(lactic-co-glycolic acids) and PEG-IFN-α in poly(lactic-co-glycolic acid)-polyethylene glycol) was below 130 nm diameter. IFN-α encapsulation efficiency of the nanoparticles was between 78 and 91%. Conclusion: The in vitro drug release studies conducted in phosphate-buffered saline and human plasma highlighted the role of incubation medium on the IFN release from the nanoparticles. The PEG-IFN-α in poly(lactic-co-glycolic acid)-polyethylene glycol was the most promising nanoparticle among the four formulations because of its remarkably constant release in both phosphate-buffered saline and plasma. </jats:p

Co-encapsulation of human serum albumin and superparamagnetic iron oxide in PLGA nanoparticles: Part II. Effect of process variables on protein model drug encapsulation efficiency.

This study investigates encapsulation efficiency of model drug, encapsulated by magnetic poly d,l-lactic-co-glycolic acid (PLGA) nanoparticles (NPs). This is the following part of our preceding paper, which is referred in this paper as Part I. Magnetic nanoparticles and model drug human serum albumin (HSA)-loaded PLGA NPs were prepared by the double emulsion solvent evaporation method. Among five important process variables, concentration of PLGA and concentration of HSA in the inner aqueous phase along with their cross-effect had the strongest influence on the encapsulation efficiency. Encapsulation efficiency of nanoparticles ranged from 18% to 97% depending on the process conditions. Higher encapsulation efficiencies can be achieved by using low HSA and high PLGA concentrations. The optimization process, carried out by exact mathematical tools using GAMSTM/MINOS software makes it easier to find out optimum process conditions to achieve comparatively high encapsulation efficiency (e.g. 92.3%) for relatively small-sized PLGA NPs (e.g. 155 nm)

Tailoring the dispersibility of non-covalent functionalized multi-walled carbon nanotube (MWCNT) nanosuspension using shellac (SL) bio-resin: Structure-property relationship and cytotoxicity of shellac coated carbon nanotubes (SLCNTs)

This study first reports the use of natural thermoplastic bio-resin shellac (SL) to functionalize multi-walled carbon nanotubes (MWCNTs). The MWCNTs were coated with 5, 10, and 15 wt% SL solutions to fabricate SLCNT nanocomposites which are highly dispersible and stable in solution. Enhanced surface charge imparted long-term stabilization of SLCNT nanosuspension. Microscopic analysis revealed distinct dispersion of nanotubes and a thin layer of SL on the surface of nanotubes in the nanocomposite system. FTIR and Raman spectroscopy confirmed well interaction between SL and MWCNT in the nanocomposites. It was disclosed by the microstructure analysis that the SL concentration affects the lattice parameters of SLCNT nanocomposites. The thermal stability of SLCNT was impressive compared to MWCNT. According to the ROS (reactive oxygen species) generation profile and cell viability study, SLCNTs have reduced adverse effects on cells. Therefore, the results confirm that shellac can significantly improve the stability of MWCNT and reduce the cytotoxicity to facilitate their widespread applications

Co-encapsulation of human serum albumin and superparamagnetic iron oxide in PLGA nanoparticles: Part I. Effect of process variables on the mean size

PLGA (poly d,l-lactic-co-glycolic acid) nanoparticles (NPs) encapsulating magnetite nanoparticles (MNPs) along with a model drug human serum albumin (HSA) were prepared by double emulsion solvent evaporation method. This Part I will focus on size and size distribution of prepared NPs, whereas encapsulation efficiency will be discussed in Part II. It was found that mean hydrodynamic particle size was influenced by five important process variables. To explore their effects, a five-factorial, three-level experimental design and statistical analysis were carried out using STATISTICA® software. Effect of process variables on the mean size of nanoparticles was investigated and finally conditions to minimize size of NPs were proposed. GAMS™/MINOS software was used for optimization. The mean hydrodynamic size of nanoparticles ranged from 115 to 329 nm depending on the process conditions. Smallest possible mean particle size can be achieved by using low polymer concentration and high dispersion energy (enough sonication time) along with small aqueous/organic volume ratio

Iron oxide nanoparticles in magnetic drug targeting and ferroptosis-based cancer therapy

Iron oxide (IO) nanoparticles (NPs) have gained significant attention in the field of biomedicine, particularly in drug targeting and cancer therapy. Their potential in magnetic drug targeting (MDT) and ferroptosis-based cancer therapy is highly promising. IO NPs serve as an effective drug delivery system (DDS), utilizing external magnetic fields (EMFs) to target cancer cells while minimizing damage to healthy organs. Additionally, IO NPs can generate reactive oxygen species (ROS) and induce ferroptosis, resulting in cytotoxic effects on cancer cells. This article explores how IO NPs can potentially revolutionize cancer research, focusing on their applications in MDT and ferroptosis-based therapy