scholarly journals Chitosan capping enzyme-responsive hollow mesoporous silica nanoplatforms for colon specific drug delivery

2020 ◽  
Author(s):  
Defu Cai ◽  
Cuiyan Han ◽  
Chang Liu ◽  
Xiaoxing Ma ◽  
Jiayi Qian ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Mesoporous Silica ◽  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Specific Drug ◽  
Colon Specific Drug Delivery ◽  
Hollow Mesoporous Silica

Abstract In summary, an enzyme-responsive colon specific drug delivery system was developed based on hollow mesoporous silica sphere (HMSS), in which the biodegradable chitosan (CS) was gated on the openings of HMSS through cleavable azo bonds (HMSS-N=N-CS). Doxorubicin (DOX) was encapsulated into the hollow cavity and mesopores of HMSS, and HMSS-N=N-CS/DOX showed a high loading amount of 35.2%. X-ray diffraction (XRD) experiment proved that the DOX loaded in the HMSS-N=N-CS was in a non–crystalline state. In vitro drug release experiments proved that HMSS-N=N-CS/DOX showed an enzyme-responsive drug release property. The grafted CS could increase the biocompatibility and stability of HMSS, and reduce the protein adsorption on the surface of HMSS. The gastrointestinal mucosa irritation and cell cytotoxicity results indicated the good biocompatibility of HMSS and HMSS-N=N-CS. The confocal laser scanning microscope (CLSM) and flow cytometry technique (FCM) results indicated that the cellular uptake of DOX was obviously increased after the HMSS-N=N-CS/DOX was preincubated with colonic enzyme mixture. Cell viability result indicated that HMSS-N=N-CS/DOX incubated with colon enzyme showed an increased cytotoxicity and the IC50 value was three time less than that of HMSS-N=N-CS/DOX group. The present work will lay the foundation for subsequent research on mesoporous carriers for oral colon-specific drug delivery.

scholarly journals Chitosan-capped enzyme-responsive hollow mesoporous silica nanoplatforms for colon-specific drug delivery

2020 ◽  
Author(s):  
Defu Cai ◽  
Cuiyan Han ◽  
Chang Liu ◽  
Xiaoxing Ma ◽  
Jiayi Qian ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Mesoporous Silica ◽  
Specific Drug ◽  
Hollow Mesoporous Silica Spheres ◽  
Good Biocompatibility ◽  
Colon Specific Drug Delivery ◽  
Loading Amount ◽  
Hollow Mesoporous Silica

Abstract An enzyme-responsive colon-specific delivery system was developed based on hollow mesoporous silica spheres (HMSS) to which biodegradable chitosan (CS) was attached via cleavable azo bonds (HMSS-N=N-CS). Doxorubicin (DOX) was encapsulated in a noncrystalline state in the hollow cavity and mesopores of HMSS with the high loading amount of 35.2%. In vitro drug release proved that HMSS-N=N-CS/DOX performed enzyme-responsive drug release. The grafted CS could increase the biocompatibility and stability, and reduce the protein adsorption on HMSS. Gastrointestinal mucosa irritation and cell cytotoxicity results indicated the good biocompatibility of HMSS and HMSS-N=N-CS. Cellular uptake results indicated that the uptake of DOX was obviously increased after HMSS-N=N-CS/DOX was preincubated with a colonic enzyme mixture. HMSS-N=N-CS/DOX incubated with colon enzymes showed increased cytotoxicity, and its IC 50 value was three times lower than that of HMSS-N=N-CS/DOX group without colon enzymes. The present work lays the foundation for subsequent research on mesoporous carriers for oral colon-specific drug delivery.

scholarly journals Chitosan-capped enzyme-responsive hollow mesoporous silica nanoplatforms for colon-specific drug delivery

2020 ◽  
Author(s):  
Defu Cai ◽  
Cuiyan Han ◽  
Chang Liu ◽  
Xiaoxing Ma ◽  
Jiayi Qian ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Mesoporous Silica ◽  
Specific Drug ◽  
Hollow Mesoporous Silica Spheres ◽  
Good Biocompatibility ◽  
Colon Specific Drug Delivery ◽  
Loading Amount ◽  
Hollow Mesoporous Silica

Abstract An enzyme-responsive colon-specific delivery system was developed based on hollow mesoporous silica spheres (HMSS) to which biodegradable chitosan (CS) was attached via cleavable azo bonds (HMSS-N=N-CS). Doxorubicin (DOX) was encapsulated in a noncrystalline state in the hollow cavity and mesopores of HMSS with the high loading amount of 35.2%. In vitro drug release proved that HMSS-N=N-CS/DOX performed enzyme-responsive drug release. The grafted CS could increase the biocompatibility and stability, and reduce the protein adsorption on HMSS. Gastrointestinal mucosa irritation and cell cytotoxicity results indicated the good biocompatibility of HMSS and HMSS-N=N-CS. Cellular uptake results indicated that the uptake of DOX was obviously increased after HMSS-N=N-CS/DOX was preincubated with a colonic enzyme mixture. HMSS-N=N-CS/DOX incubated with colon enzymes showed increased cytotoxicity, and its IC50 value was three times lower than that of HMSS-N=N-CS/DOX group without colon enzymes. The present work lays the foundation for subsequent research on mesoporous carriers for oral colon-specific drug delivery.

A Facile Synthesis of Acid-Activatable Nanoparticles for Efficient Intracellular Doxorubicin Release

2017 ◽  
Vol 46 ◽  
pp. 20-30 ◽  
Author(s):  
Cao Ming ◽  
Xiao Wan Song ◽  
Yu Jiao Zhang ◽  
Chang Zhi Xu ◽  
Peng Chen ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Hela Cells ◽  
Laser Scanning ◽  
Human Cancer ◽  
Polymeric Nanoparticles ◽  
Confocal Laser Scanning Microscope ◽  
Ph Sensitive ◽  
Confocal Laser ◽  
Cell Nuclei

pH responsive polymeric nanoparticles have emerged as a promising technology platform for targeted and controlled drug delivery in recent years. In this paper, endosomal pH-activatable doxorubicin (DOX) and core-crosslinked polymeric nanoparticles (DCNPs) were prepared and investigated for potent growth inhibition of human cancer cells in vitro. In vitro drug release studies, DOX conjugated nanoparticles with hydrazone bond showed a pH sensitive release phenomenon, that is, the releasing is significantly faster at mildly acidic condition with pH of 5.5 than that at physiological condition. Confocal laser scanning microscope (CLSM) observations revealed that DOX conjugated nanoparticles delivered and released DOX into the cytosols as well as cell nuclei of Hela cells following 6 h incubation. MTT assays demonstrated that these pH-sensitive DOX nanoparticles exhibited high antitumor effect to HeLa cells. The conjugated DOX polymeric nanoparticles may be a promising candidate as a nanoscale and pH-sensitive drug delivery vehicle for cancer therapy.

scholarly journals Synthesis, in-vitro characterization and pharmacological evaluation of conjugates of flurbiprofen and polysaccharides for colon specific drug delivery

2019 ◽  
Vol 9 (2) ◽  
pp. 316-320
Author(s):  
P Soni ◽  
K Soni ◽  
GP Choudhary
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Specific Drug ◽  
Glycosidic Linkage ◽  
In Vitro Drug Release ◽  
In Vitro Characterization ◽  
Microbial System ◽  
Colon Specific Drug Delivery ◽  
Upper Gastrointestinal

The aim of the study was to prepare site specific drug delivery of flurbiprofen using polysaccharides by the formation of glycosidic linkage which is hydrolysed by the microflora present in colon. This approach prevents drug release in the upper gastrointestinal environment. Due to the minimal degradation of conjugates in upper Git, the in vitro drug release in SGF, SIF and SCF was found upto 4.26±0.03%, 12.41±0.08% and 92.72±3.33% respectively. Keywords: Colon specific drug delivery, Conjugates, Flurbiprofen, Microbial system.

scholarly journals Grape Seed Extract as a Potential Remineralizing Agent: A Comparative in vitro Study

2012 ◽  
Vol 13 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Shiny Benjamin ◽  
Roshni LNU ◽  
Sabeena Susan Thomas ◽  
Mohan Thomas Nainan
Keyword(s):  
Laser Scanning ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Confocal Laser Scanning Microscope ◽  
Seed Extract ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Caries Lesions ◽  
Calcium Glycerophosphate

ABSTRACT Objective Remineralization is an effective treatment that may stop or reverse early tooth decay. Grape seed extract (GSE) is the potential remineralizing agent under investigation. Materials and methods Sound human tooth sections were obtained from the cervical portion of the root and stored in demineralizing solution at 37°C for 96 hours to induce artificial root caries lesions. The sections were divided into four treatment groups including 6.5% grape seed extract, sodium monofluorophosphate (220 ppm) with 0.05% calcium glycerophosphate, 0.5% calcium glycerophosphate and control (no treatment). An in vitro pH cycling model was used to cycle the demineralized specimens through treatment solutions, acidic buffer and neutral buffer for 8 days at 6 cycles per day. Subsequently, they were evaluated using confocal laser scanning microscope. Data were analyzed using analysis of variance (p < 0.05). Results GSE revealed less demineralization and more remineralization compared with other groups. Conclusion GSE promotes remineralization of artificial root caries lesions. Clinical significance The search for the perfect remineralizing agent continues to this day. GSE could be a welcome addition to the remineralization armamentarium. Abbreviations and acronyms GSE: Grape seed extract; ppm: Parts per million; CaGP: Calcium glycerophosphate; CLSM: Confocal laser scanning microscope; ANOVA: Analysis of variance; PA: Proanthocyanidin; CEJ: Cementoenamel junction; mM: Millimole; CaCl2.2H2O: Calcium chloride dihydrate; KH2PO4: Potassium dehydrate phosphate; K2HPO4: Dipotassium phosphate; dH2O: Deionized water; w/v: Weight by volume; ROD: Relative optical density; nm: Nanometer; SD: Standard deviation. How to cite this article Benjamin S, Roshni, Thomas SS, Nainan MT. Grape Seed Extract as a Potential Remineralizing Agent: A Comparative in vitro Study. J Contemp Dent Pract 2012;13(4):425-430.

scholarly journals SYNTHESIS AND IN VITRO BIODEGRADATION OF AZO POLYMER FOR COLON-SPECIFIC DRUG DELIVERY

2009 ◽  
Vol 007 (1) ◽  
pp. 8-14
Author(s):  
Junying LAI ◽  
Wenjing LI ◽  
Hongjun WANG ◽  
Kehua TU ◽  
Liqun WANG
Keyword(s):  
Drug Delivery ◽  
Specific Drug ◽  
Azo Polymer ◽  
Colon Specific Drug Delivery

Synthesis, singlet oxygen generation, photocytotoxicity and subcellular localization of azobisporphyrins as potentially photodynamic therapeutic agents in vitro cell study

2017 ◽  
Vol 21 (02) ◽  
pp. 122-127 ◽  
Author(s):  
Yunman Zheng ◽  
Sizhe Zhu ◽  
Lijun Jiang ◽  
Fengshou Wu ◽  
Chi Huang ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Hela Cells ◽  
Cellular Localization ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Oxygen Generation ◽  
Scanning Confocal Microscopy

Three azobisporphyrins (Por1, Por2 and Por3) were synthesized by coupling two molecules of (4-nitrophenyl/pyridyl) porphyrins in the presence of KOH/butanol. The structures of porphyrins were confirmed by UV, IR, NMR and mass spectra and elemental analysis. With tetraphenylporphyrin (H2TPP) as a control, the singlet oxygen (1O[Formula: see text] generation of porphyrins was evaluated through 1,3-diphenylisobenzofuran (DPBF) method. The order of ability to generate 1O2 for three azobisporphyrins was Por 1 [Formula: see text]Por 2 > Por 3[Formula: see text] H2TPP. The photocytotoxicity and sub-cellular localization of azobisporphyrins over Hela cells were studied through MTT analysis and confocal laser scanning microscope, respectively. The results indicated Por 1 and Por 2 displayed the low dark-cytotoxicity, while Por 3 induced a concentration-dependent cytotoxicity to Hela cells with the concentration of porphyrins ranging from 1 to 100 [Formula: see text] M. With the light dose at 4 J/cm2, Por 3 killed more than 60% Hela cells at 2 [Formula: see text] M, indicating a high photocytoxicity. As seen from the laser scanning confocal microscopy images, Por 3 was mainly localized in cell membrane, while Por 1 and Por 2 do not displayed significant fluorescent emission in Hela cells. These results suggest the synthesized cationic azobisporphyrin could be used as a potential therapeutic agent for photodynamic therapy of cancers.

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