Compartmentalized Polymeric Nanoparticles Deliver Vancomycin in a pH-Responsive Manner

Vancomycin (VCM) is a last resort antibiotic in the treatment of severe Gram-positive infections. However, its administration is limited by several drawbacks such as: strong pH-dependent charge, tendency to aggregate, low bioavailability, and poor cellular uptake. These drawbacks were circumvented by engineering pH-responsive nanoparticles (NPs) capable to incorporate high VCM payload and deliver it specifically at slightly acidic pH corresponding to infection sites. Taking advantage of peculiar physicochemical properties of VCM, here we show how to incorporate VCM efficiently in biodegradable NPs made of poly(lactic-co-glycolic acid) and polylactic acid (co)polymers. The NPs were prepared by a simple and reproducible method, establishing strong electrostatic interactions between VCM and the (co)polymers’ end groups. VCM payloads reached up to 25 wt%. The drug loading mechanism was investigated by solid state nuclear magnetic resonance spectroscopy. The engineered NPs were characterized by a set of advanced physicochemical methods, which allowed examining their morphology, internal structures, and chemical composition on an individual NP basis. The compartmentalized structure of NPs was evidenced by cryogenic transmission electronic microscopy, whereas the chemical composition of the NPs’ top layers and core was obtained by electron microscopies associated with energy-dispersive X-ray spectroscopy. Noteworthy, atomic force microscopy coupled to infrared spectroscopy allowed mapping the drug location and gave semiquantitative information about the loadings of individual NPs. In addition, the NPs were stable upon storage and did not release the incorporated drug at neutral pH. Interestingly, a slight acidification of the medium induced a rapid VCM release. The compartmentalized NPs could find potential applications for controlled VCM release at an infected site with local acidic pH.

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Conjugation of a smart polymer to doxorubicin through a pH-responsive bond for targeted drug delivery and improving drug loading on graphene oxide

RSC Advances ◽

10.1039/d1ra02361f ◽

2021 ◽

Vol 11 (31) ◽

pp. 18809-18817

Author(s):

Ali Bina ◽

Heidar Raissi ◽

Hassan Hashemzadeh ◽

Farzaneh Farzad

Keyword(s):

Drug Delivery ◽

Graphene Oxide ◽

Anticancer Drug ◽

Targeted Drug Delivery ◽

Polymeric Nanoparticles ◽

Drug Loading ◽

Ph Responsive ◽

Smart Polymer ◽

Anticancer Drug Delivery ◽

Targeted Drug

Polymeric nanoparticles have emerged as efficient carriers for anticancer drug delivery because they can improve the solubility of hydrophobic drugs and also can increase the bio-distribution of drugs throughout the bloodstream.

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Polymeric Nanoparticles for Brain Drug Delivery - A Review

Current Drug Metabolism ◽

10.2174/1389200221666200508074348 ◽

2020 ◽

Vol 21 (9) ◽

pp. 649-660

Author(s):

Subashini Raman ◽

Syed Mahmood ◽

Ayah R. Hilles ◽

Md Noushad Javed ◽

Motia Azmana ◽

...

Keyword(s):

Drug Delivery ◽

Surface Modification ◽

Polymeric Nanoparticles ◽

Drug Loading ◽

Preparation Methods ◽

Brain Drug Delivery ◽

Polymeric Nanoparticle ◽

Relationship Of ◽

The Relationship ◽

The Brain

Background: Blood-brain barrier (BBB) plays a most hindering role in drug delivery to the brain. Recent research comes out with the nanoparticles approach, is continuously working towards improving the delivery to the brain. Currently, polymeric nanoparticle is extensively involved in many therapies for spatial and temporal targeted areas delivery. Methods: We did a non-systematic review, and the literature was searched in Google, Science Direct and PubMed. An overview is provided for the formulation of polymeric nanoparticles using different methods, effect of surface modification on the nanoparticle properties with types of polymeric nanoparticles and preparation methods. An account of different nanomedicine employed with therapeutic agent to cross the BBB alone with biodistribution of the drugs. Results: We found that various types of polymeric nanoparticle systems are available and they prosper in delivering the therapeutic amount of the drug to the targeted area. The effect of physicochemical properties on nanoformulation includes change in their size, shape, elasticity, surface charge and hydrophobicity. Surface modification of polymers or nanocarriers is also vital in the formulation of nanoparticles to enhance targeting efficiency to the brain. Conclusion: More standardized methods for the preparation of nanoparticles and to assess the relationship of surface modification on drug delivery. While the preparation and its output like drug loading, particle size, and charge, permeation is always conflicted, so it requires more attention for the acceptance of nanoparticles for brain delivery.

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A pH-Responsive Foam Formulated with PAA/Gemini 12-2-12 Complexes

Colloids and Interfaces ◽

10.3390/colloids5030037 ◽

2021 ◽

Vol 5 (3) ◽

pp. 37

Author(s):

Hernán Martinelli ◽

Claudia Domínguez ◽

Marcos Fernández Leyes ◽

Sergio Moya ◽

Hernán Ritacco

Keyword(s):

Surface Tension ◽

Dynamic Surface Tension ◽

Foam Formation ◽

Ph Responsive ◽

Dynamic Surface ◽

X Ray ◽

Equilibrium Surface Tension ◽

Potential Applications ◽

The Stability ◽

Air Interfaces

In the search for responsive complexes with potential applications in the formulation of smart dispersed systems such as foams, we hypothesized that a pH-responsive system could be formulated with polyacrylic acid (PAA) mixed with a cationic surfactant, Gemini 12-2-12 (G12). We studied PAA-G12 complexes at liquid–air interfaces by equilibrium and dynamic surface tension, surface rheology, and X-ray reflectometry (XRR). We found that complexes adsorb at the interfaces synergistically, lowering the equilibrium surface tension at surfactant concentrations well below the critical micelle concentration (cmc) of the surfactant. We studied the stability of foams formulated with the complexes as a function of pH. The foams respond reversibly to pH changes: at pH 3.5, they are very stable; at pH > 6, the complexes do not form foams at all. The data presented here demonstrate that foam formation and its pH responsiveness are due to interfacial dynamics.

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Rhein laden pH-responsive polymeric nanoparticles for treatment of osteoarthritis

AMB Express ◽

10.1186/s13568-020-01095-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Bo Hu ◽

Feng Gao ◽

Chunbao Li ◽

Boqing Zhang ◽

Mingyang An ◽

...

Keyword(s):

Polymeric Nanoparticles ◽

Ph Responsive

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Cholesterol Levels Affect the Performance of AuNPs-Decorated Thermo-Sensitive Liposomes as Nanocarriers for Controlled Doxorubicin Delivery

Pharmaceutics ◽

10.3390/pharmaceutics13070973 ◽

2021 ◽

Vol 13 (7) ◽

pp. 973

Author(s):

Mónica C. García ◽

Nabila Naitlho ◽

José Manuel Calderón-Montaño ◽

Estrella Drago ◽

Manuela Rueda ◽

...

Keyword(s):

Drug Release ◽

Cancer Cells ◽

Electrostatic Interactions ◽

Drug Loading ◽

Gradient Methods ◽

Spherical Shape ◽

Morphological Properties ◽

Ovarian Cancer Cells ◽

Cholesterol Levels ◽

L1 And L2

Stimulus-responsive liposomes (L) for triggering drug release to the target site are particularly useful in cancer therapy. This research was focused on the evaluation of the effects of cholesterol levels in the performance of gold nanoparticles (AuNPs)-functionalized L for controlled doxorubicin (D) delivery. Their interfacial and morphological properties, drug release behavior against temperature changes and cytotoxic activity against breast and ovarian cancer cells were studied. Langmuir isotherms were performed to identify the most stable combination of lipid components. Two mole fractions of cholesterol (3.35 mol% and 40 mol%, L1 and L2 series, respectively) were evaluated. Thin-film hydration and transmembrane pH-gradient methods were used for preparing the L and for D loading, respectively. The cationic surface of L allowed the anchoring of negatively charged AuNPs by electrostatic interactions, even inducing a shift in the zeta potential of the L2 series. L exhibited nanometric sizes and spherical shape. The higher the proportion of cholesterol, the higher the drug loading. D was released in a controlled manner by diffusion-controlled mechanisms, and the proportions of cholesterol and temperature of release media influenced its release profiles. D-encapsulated L preserved its antiproliferative activity against cancer cells. The developed liposomal formulations exhibit promising properties for cancer treatment and potential for hyperthermia therapy.

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The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽

10.3390/molecules26061661 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1661

Author(s):

Katarzyna Adamiak ◽

Katarzyna Lewandowska ◽

Alina Sionkowska

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Infrared Spectroscopy ◽

Rheological Properties ◽

Silver Carp ◽

Shear Tests ◽

Force Microscopy ◽

Atomic Force ◽

Film Forming ◽

Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

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Acidic pH-responsive changes of DNA structure and surface dynamics as probed with ultrasensitive Raman spectroscopy

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy ◽

10.1016/j.saa.2021.119866 ◽

2021 ◽

Vol 258 ◽

pp. 119866

Author(s):

Cristina M. Muntean ◽

Nicoleta E. Dina ◽

Ioan Bratu ◽

Carmen Tripon ◽

Sorina Niţu (Năstase) ◽

...

Keyword(s):

Raman Spectroscopy ◽

Dna Structure ◽

Acidic Ph ◽

Surface Dynamics ◽

Ph Responsive

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Solute in high arctic glacier snow cover and its impact on runoff chemistry

Annals of Glaciology ◽

10.3189/1998aog26-1-156-160 ◽

1998 ◽

Vol 26 ◽

pp. 156-160 ◽

Cited By ~ 3

Author(s):

Richard Hodgkins ◽

Martyn Tranter

Keyword(s):

Chemical Composition ◽

Atmospheric Transport ◽

Total Concentration ◽

High Arctic ◽

Sea Salt ◽

Acidic Ph ◽

Sea Salt Aerosol ◽

Wet Snow ◽

Potential Contributor ◽

Arctic Glacier

The chemical composition of snow and meltwater in the 13 km2 catchment of Scott Turnerbreen, Svalbard, was investigated during the spring and summer of 1993. This paper assesses the provenance of solute in the snowpack and its impact on runoff chemistry. Dry snow contains 420μeql-1 of solute, is slightly acidic (pH 5.4) and is dominated by Na+ and Cl-. Wet snow is more dilute (total concentration 340μeql-1), and less acidic (pH 5.9). This is consistent with the elution of ions from the snowpack by meltwater. Snowpack solute can be partitioned into the following fractions: sea-salt aerosol, acid aerosol and crustal. About 98% of snowpack solute is sea salt, yielding 22000 kg km-2a-1. The behaviour of snowpack-derived Cl- in runoff is distinctive, peaking at over 800 μeql-1 early in the melt season as runoff picks up, before declining quasi-exponentially. This represents the discharge of snowmelt concentrated by elution within the snowpack which subsequently becomes relatively dilute. A solute yield of 140 kg km-2 a-1 can be attributed to anthropogenically generated acid aerosols, representing long-range atmospheric transport of pollutants, a potential contributor to Arctic runoff acidification.

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Preparation and Characterization of Chitosan-Casein Phosphopeptides Biocomposite Coatings on the Medical Titanium Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.480-481.1065 ◽

2011 ◽

Vol 480-481 ◽

pp. 1065-1069

Author(s):

Bin Liu ◽

Lin Wang ◽

Yin Zhong Bu ◽

Sheng Rong Yang ◽

Jin Qing Wang

Keyword(s):

Photoelectron Spectroscopy ◽

Attenuated Total Reflectance ◽

Ti Alloy ◽

Force Microscopy ◽

Implant Materials ◽

Atomic Force ◽

Casein Phosphopeptides ◽

Potential Applications ◽

First Time

Titanium (Ti) and its alloys have been applied in orthopedics as one of the most popular biomedical metallic implant materials. In this work, to enhance the bioactivity, the surface of Ti alloy pre-modified by silane coupling agent and glutaraldehyde was covalently grafted with chitosan (CS) via biochemical multistep self-assembled method. Then, for the first time, the achieved surface was further immobilized with casein phosphopeptides (CPP), which are one group of bioactive peptides released from caseins in the digestive tract and can facilitate the calcium adsorption and usage, to form CS-CPP biocomposite coatings. The structure and composition of the fabricated coatings were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). As the experimental results indicated, multi-step assembly was successfully performed, and the CS and CPP were assembled onto the Ti alloy surface orderly. It is anticipated that the Ti alloys modified by CS-CPP biocomposite coatings will find potential applications as implant materials in biomedical fields.

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