scholarly journals Myristic Acid Coated Protein Immobilised Mesoporous Silica Particles as pH Induced Oral Delivery System for the Delivery of Biomolecules

2019 ◽  
Vol 12 (4) ◽  
pp. 153
Author(s):  
Vivek Trivedi ◽  
Ruchir Bhomia ◽  
John C Mitchell

Solid core drug delivery systems (SCDDS) were prepared for the oral delivery of biomolecules using mesoporous silica as core, bovine haemoglobin (bHb) as model drug and supercritical fluid (SCF) processing as encapsulation technique. The use of organic solvents or harsh processing conditions in the development of drug delivery systems for biomolecules can be detrimental for the structural integrity of the molecule. Hence, the coating on protein-immobilised particles was performed via supercritical carbon dioxide (scCO2) processing at a temperature lower than the melting point of myristic acid (MA) to avoid any thermal degradation of bHb. The SCDDS were prepared by bHb immobilisation on mesoporous silica followed by myristic acid (MA) coating at 43 °C and 100 bar in scCO2. bHb-immobilised silica particles were also coated via solvent evaporation (SE) to compare the protein release with scCO2 processed formulations. In both cases, MA coating provided required enteric protection and restricted the bHb release for the first two hours in simulated gastric fluid (SGF). The protein release was immediate upon the change of media to simulated intestinal fluid (SIF), reaching 70% within three hours. The release from SCF processed samples was slower than SE formulations, indicating superior surface coverage of MA on particles in comparison to the SE method. Most importantly, the protein conformation remained unchanged after the release from SCDDS as confirmed by circular dichroism. This study clearly demonstrates that the approach involving protein immobilisation on silica and scCO2 assisted melt-coating method can protect biomolecules from gastric environment and provide the required release of a biologic in intestine without any untoward effects on protein conformation during processing or after release.

2019 ◽  
Author(s):  
Teodora Popova ◽  
Borislav Tzankov ◽  
Christina Voycheva ◽  
Krassimira Yoncheva ◽  
Nikolai Lambov

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 15 ◽  
Author(s):  
Andreea Madalina Pandele ◽  
Corina Andronescu ◽  
Adi Ghebaur ◽  
Sorina Alexandra Garea ◽  
Horia Iovu

A high number of studies support the use of mesoporous silica nanoparticles (MSN) as carriers for drug delivery systems due to its high biocompatibility both in vitro and in vivo, its large surface area, controlled pore size and, more than this, its good excretion capacity from the body. In this work we attempt to establish the optimal encapsulation parameters of benzalkonium chloride (BZC) into MSN and further study its drug release. The influence of different parameters towards the drug loading in MSN such as pH, contact time and temperature were considered. The adsorption mechanism of the drug has been determined by using the equilibrium data. The modification process was proved using several methods such as Fourier transform-infrared (FT-IR), ultraviolet-visible (UV-VIS), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). Since MSN shows a lower drug release amount due to the agglomeration tendency, in order to increase MSN dispersion and drug release amount from MSN, two common biocompatible and biodegradable polymers were used as polymer matrix in which the MSN-BZC can be dispersed. The drug release profile of the MSN-BZC and of the synthesized hybrid materials were studied both in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Polymer-MSN-BZC hybrid materials exhibit a higher drug release percent than the pure MSN-BZC when a higher dispersion is achieved. The dispersion of MSN into the hybrid materials was pointed out in scanning electron microscope (SEM) images. The release mechanism was determined using four mathematic models including first-order, Higuchi, Korsmeyer–Peppas and Weibull.


2013 ◽  
Vol 40 (10) ◽  
pp. 1014
Author(s):  
Xiao-Hong HAO ◽  
Cui-Miao ZHANG ◽  
Xiao-Long LIU ◽  
Xing-Jie LIANG ◽  
Guang JIA ◽  
...  

2020 ◽  
Vol 20 (11) ◽  
pp. 1001-1016
Author(s):  
Sandra Ramírez-Rave ◽  
María Josefa Bernad-Bernad ◽  
Jesús Gracia-Mora ◽  
Anatoly K. Yatsimirsky

Hybrid materials based on Mesoporous Silica Nanoparticles (MSN) have attracted plentiful attention due to the versatility of their chemistry, and the field of Drug Delivery Systems (DDS) is not an exception. MSN present desirable biocompatibility, high surface area values, and a well-studied surface reactivity for tailoring a vast diversity of chemical moieties. Particularly important for DDS applications is the use of external stimuli for drug release. In this context, light is an exceptional alternative due to its high degree of spatiotemporal precision and non-invasive character, and a large number of promising DDS based on photoswitchable properties of azobenzenes have been recently reported. This review covers the recent advances in design of DDS using light as an external stimulus mostly based on literature published within last years with an emphasis on usually overlooked underlying chemistry, photophysical properties, and supramolecular complexation of azobenzenes.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 460
Author(s):  
Minja Mladenović ◽  
Ibrahim Morgan ◽  
Nebojša Ilić ◽  
Mohamad Saoud ◽  
Marija V. Pergal ◽  
...  

Ruthenium complexes are attracting interest in cancer treatment due to their potent cytotoxic activity. However, as their high toxicity may also affect healthy tissues, efficient and selective drug delivery systems to tumour tissues are needed. Our study focuses on the construction of such drug delivery systems for the delivery of cytotoxic Ru(II) complexes upon exposure to a weakly acidic environment of tumours. As nanocarriers, mesoporous silica nanoparticles (MSN) are utilized, whose surface is functionalized with two types of ligands, (2-thienylmethyl)hydrazine hydrochloride (H1) and (5,6-dimethylthieno[2,3-d]pyrimidin-4-yl)hydrazine (H2), which were attached to MSN through a pH-responsive hydrazone linkage. Further coordination to ruthenium(II) center yielded two types of nanomaterials MSN-H1[Ru] and MSN-H2[Ru]. Spectrophotometric measurements of the drug release kinetics at different pH (5.0, 6.0 and 7.4) confirm the enhanced release of Ru(II) complexes at lower pH values, which is further supported by inductively coupled plasma optical emission spectrometry (ICP-OES) measurements. Furthermore, the cytotoxicity effect of the released metallotherapeutics is evaluated in vitro on metastatic B16F1 melanoma cells and enhanced cancer cell-killing efficacy is demonstrated upon exposure of the nanomaterials to weakly acidic conditions. The obtained results showcase the promising capabilities of the designed MSN nanocarriers for the pH-responsive delivery of metallotherapeutics and targeted treatment of cancer.


2020 ◽  
Vol 8 (13) ◽  
pp. 2636-2649
Author(s):  
Yuli Bai ◽  
Rui Zhou ◽  
Lei Wu ◽  
Yaxian Zheng ◽  
Xi Liu ◽  
...  

Endowing the NPs with specific surface features of dendritic oligopeptides holds great potential for the oral delivery of peptide/protein drugs.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 187 ◽  
Author(s):  
Alessandra Adrover ◽  
Patrizia Paolicelli ◽  
Stefania Petralito ◽  
Laura Di Muzio ◽  
Jordan Trilli ◽  
...  

In this study, gellan gum (GG), a natural polysaccharide, was used to fabricate spherical porous beads suitable as sustained drug delivery systems for oral administration. GG was cross-linked with calcium ions to prepare polymeric beads. Rheological studies and preliminary experiments of beads preparation allowed to identify the GG and the CaCl2 concentrations suitable for obtaining stable and spherical particles. GG beads were formed, through ionotropic gelation technique, with and without the presence of the synthetic clay laponite. The resultant beads were analyzed for dimensions (before and after freeze-drying), morphological aspects and ability to swell in different media miming biological fluids, namely SGF (Simulated Gastric Fluid, HCl 0.1 M) and SIF (Simulated Intestinal Fluid, phosphate buffer, 0.044 M, pH 7.4). The swelling degree was lower in SGF than in SIF and further reduced in the presence of laponite. The GG and GG-layered silicate composite beads were loaded with two model drugs having different molecular weight, namely theophylline and cyanocobalamin (vitamin B12) and subjected to in-vitro release studies in SGF and SIF. The presence of laponite in the bead formulation increased the drug entrapment efficiency and slowed-down the release kinetics of both drugs in the gastric environment. A moving-boundary swelling model with “diffuse” glassy-rubbery interface was proposed in order to describe the swelling behavior of porous freeze-dried beads. Consistently with the swelling model adopted, two moving-boundary drug release models were developed to interpret release data from highly porous beads of different drugs: drug molecules, e.g., theophylline, that exhibit a typical Fickian behavior of release curves and drugs, such as vitamin B12, whose release curves are affected by the physical/chemical interaction of the drug with the polymer/clay complex. Theoretical results support the experimental observations, thus confirming that laponite may be an effective additive for fabricating sustained drug delivery systems.


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