scholarly journals Chitosan-Based Coacervate Polymers for Propolis Encapsulation: Release and Cytotoxicity Studies

2020 ◽  
Vol 21 (12) ◽  
pp. 4561 ◽  
Author(s):  
Tabata Sato ◽  
Daphne Mello ◽  
Luana Vasconcellos ◽  
Artur Valente ◽  
Alexandre Borges

Chitosan-DNA (CS-DNA) and Chitosan-Pectin (CS-P) hydrogels were formulated as a sustained drug delivery carrier for drug delivery. For this, hydrogels were prepared by emulsion technique: mixing aqueous phase of the CS and DNA or P solution with benzyl alcohol using a high-performance dispersing instrument. Green Propolis (GP) was incorporated by imbibition: hydrogels were placed in GP aqueous solution (70 µg/mL) for 2 h. The specimens were freeze-dried and then characterized using different techniques. In vitro cell viability and morphology were also performed using the MG63 cell line. The presence of P was evidenced by the occurrence of a strong band at 1745 cm−1, also occurring in the blend. DNA and CS-DNA showed a strong band at 1650 cm−1, slightly shifted from the chitosan band. The sorption of GP induced a significant modification of the gel surface morphology and some phase separation occurs between chitosan and DNA. Drug release kinetics in water and in saliva follow a two-step mechanism. Significant biocompatibility revealed that these hydrogels were non-toxic and provided acceptable support for cell survival. Thus, the hydrogel complexation of chitosan with DNA and with Pectin provides favorable micro-environment for cell growth and is a viable alternative drug delivery system for Green Propolis.

Author(s):  
Sanjoy Das ◽  
Malay K. Das

Objective: Site-specific drug delivery into the colonic region is extremely fascinating for local treatment of various colonic diseases like ulcerative colitis, colon cancer but it should be capable of saving the drug from hydrolysis and degradation. The present study reports the application of jackfruit seed starch and its thiol derivative as a drug delivery carrier for the colon. Methods: The starch was extracted from the jackfruit seeds by water extraction method and modified by the esterification reaction with thioglycolic acid. The thiolated starch was characterized for morphology, functional and flow properties. The safety profile of the thiolated starch was confirmed by acute toxicity study in a mice model as per OECD guidelines 423. The microspheres based on thiolated starch were prepared by ionic gelation method incorporating Ibuprofen as a model drug. The prepared microspheres were characterized for particle size, drug entrapment efficiency, drug loading, compatibility study, surface morphology, in vitro drug release and release kinetics. Results: The result attributed that starch was successfully modified by the thiolation with a degree of substitution of 3.30. The size of prepared microspheres ranges from 825.5±4.58 to 857±6.24 µm, the entrapment efficiencies ranges from 69.23±1.19 to 76.15±0.83 % and the drug loading capacity ranges from 17.75±0.30 to 46.05±0.49 %. The FT-IR, DSC and XRD studies confirmed that there is no interaction within drug and excipients. The thiolated starch microspheres show the maximum release of drug at pH 7.4 in the presence of rat caecal content as compared to pH 1.2 and pH 6.8 for up to 24 h and are following first order release kinetics. Conclusion: These results suggest the application of thiolated jackfruit seed starch could be promising as a long-term drug delivery carrier for the colon.


Author(s):  
Srinivasa Rao Baratam ◽  
Vijayaratna J

Objective: The aim of the study was to develop a floating drug delivery system of levofloxacin (LVF) hemihydrate for sustained drug delivery to improve the extended retention in the stomach, oral bioavailability, and local site-specific action in the stomach. Methods: Preparation of LVF tablets using melt granulation method using hydroxypropyl methylcellulose (HPMC) K4M with sodium bicarbonate as gas generating agent. From LFTA1 to LFTA5, formulations were developed and evaluated for floating properties for swelling characteristics and in vitro drug release studies. In vitro dissolution was carried out using USP II paddle method using 0.1N HCI pH buffer at 50 rpm and samples were measured at 294 nm using ultraviolet-visible spectroscopy. Results: Obtained Fourier-transform infrared charts indicated that there is no positive evidence for the interaction between LVF and ingredients of the optimized formula. In vitro drug release was performed and drug release kinetics were evaluated using the linear regression method and were found to be followed the zero-order release by diffusion controlled release. Optimized formula was found to be LFTA4 with 20% of a polymer with 99.03% of drug release with 12 h of floating time and 32 s floating lag time. Conclusion: Matrix tablets (LFTA4) formulated employing 20% HPMC K4M are best suited to be used for gastroretentive dosage form of LVF.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kyle Battiston ◽  
Ian Parrag ◽  
Matthew Statham ◽  
Dimitra Louka ◽  
Hans Fischer ◽  
...  

AbstractPolymeric drug carriers are widely used for providing temporal and/or spatial control of drug delivery, with corticosteroids being one class of drugs that have benefitted from their use for the treatment of inflammatory-mediated conditions. However, these polymer-based systems often have limited drug-loading capacity, suboptimal release kinetics, and/or promote adverse inflammatory responses. This manuscript investigates and describes a strategy for achieving controlled delivery of corticosteroids, based on a discovery that low molecular weight corticosteroid dimers can be processed into drug delivery implant materials using a broad range of established fabrication methods, without the use of polymers or excipients. These implants undergo surface erosion, achieving tightly controlled and reproducible drug release kinetics in vitro. As an example, when used as ocular implants in rats, a dexamethasone dimer implant is shown to effectively inhibit inflammation induced by lipopolysaccharide. In a rabbit model, dexamethasone dimer intravitreal implants demonstrate predictable pharmacokinetics and significantly extend drug release duration and efficacy (>6 months) compared to a leading commercial polymeric dexamethasone-releasing implant.


Author(s):  
G D Chandrethiya ◽  
P K Shelat ◽  
M N Zaveri

PEGylated gelatin nanoparticles loaded with colchicine were prepared by ethanol precipitation method. Poly-(ethylene glycol)-5000-monomethylether (MPEG 5000), a hydrophilic polymer, was used to pegylate gelatin.  Gluteraldehyde was used as cross-linking agent. To obtain a high quality product, major formulation parameters were optimized.  Spherical particles with mean particles of 193 nm were measured by a Malvern particle size analyzer. Entrapment efficiency was found to be 71.7 ± 1.4% and determined with reverse phase high performance liquid charomatography (RP-HPLC). The in vitro drug release study was performed by dialysis bag method for a period of 168 hours. Lyophilizaton study showed sucrose at lower concentrations proved the best cryoprotectant for this formulation.  Stability study revealed that lyophilized nanoparticles were equally effective (p < 0.05) after one year of storage at 2-8°C with ambient humidity. In vitro antitumoral activity was accessed using the MCF-7 cell line by MTT assay.  The IC50 value was found to be 0.034 μg/ml for the prepared formulation. The results indicate that PEGylated gelatin nanoparticles could be utilized as a potential drug delivery for targeted drug delivery of tumors.  


Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1130
Author(s):  
Mariana Pires Figueiredo ◽  
Ana Borrego-Sánchez ◽  
Fátima García-Villén ◽  
Dalila Miele ◽  
Silvia Rossi ◽  
...  

This work presents the development of multifunctional therapeutic membranes based on a high-performance block copolymer scaffold formed by polyether (PE) and polyamide (PA) units (known as PEBA) and layered double hydroxide (LDH) biomaterials, with the aim to study their uses as wound dressings. Two LDH layer compositions were employed containing Mg2+ or Zn2+, Fe3+ and Al3+ cations, intercalated with chloride anions, abbreviated as Mg-Cl or Zn-Cl, or intercalated with naproxenate (NAP) anions, abbreviated as Mg-NAP or Zn-NAP. Membranes were structurally and physically characterized, and the in vitro drug release kinetics and cytotoxicity assessed. PEBA-loading NaNAP salt particles were also prepared for comparison. Intercalated NAP anions improved LDH–polymer interaction, resulting in membranes with greater mechanical performance compared to the polymer only or to the membranes containing the Cl-LDHs. Drug release (in saline solution) was sustained for at least 8 h for all samples and release kinetics could be modulated: a slower, an intermediate and a faster NAP release were observed from membranes containing Zn-NAP, NaNAP and Mg-NAP particles, respectively. In general, cell viability was higher in the presence of Mg-LDH and the membranes presented improved performance in comparison with the powdered samples. PEBA containing Mg-NAP sample stood out among all membranes in all the evaluated aspects, thus being considered a great candidate for application as multifunctional therapeutic dressings.


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.


2010 ◽  
Vol 1257 ◽  
Author(s):  
Andrea Fornara ◽  
Alberto Recalenda ◽  
Jian Qin ◽  
Abhilash Sugunan ◽  
Fei Ye ◽  
...  

AbstractNanoparticles consisting of different biocompatible materials are attracting a lot of interest in the biomedical area as useful tools for drug delivery, photo-therapy and contrast enhancement agents in MRI, fluorescence and confocal microscopy. This work mainly focuses on the synthesis of polymeric/inorganic multifunctional nanoparticles (PIMN) based on biocompatible di-block copolymer poly(L,L-lactide-co-ethylene glycol) (PLLA-PEG) via an emulsion-evaporation method. Besides containing a hydrophobic drug (Indomethacin), these polymeric nanoparticles incorporate different visualization agents such as superparamagnetic iron oxide nanoparticles (SPION) and fluorescent Quantum Dots (QDs) that are used as contrast agents for Magnetic Resonance Imaging (MRI) and fluorescence microscopy together. Gold Nanorods are also incorporated in such nanostructures to allow simultaneous visualization and photodynamic therapy. MRI studies are performed with different loading of SPION into PIMN, showing an enhancement in T2 contrast superior to commercial contrast agents. Core-shell QDs absorption and emission spectra are recorded before and after their loading into PIMN. With these polymeric/inorganic multifunctional nanoparticles, both MRI visualization and confocal fluorescence microscopy studies can be performed. Gold nanorods are also synthesized and incorporated into PIMN without changing their longitudinal absorption peak usable for lased excitation and phototherapy. In-vitro cytotoxicity studies have also been performed to confirm the low cytotoxicity of PIMN for further in-vivo studies.


Sign in / Sign up

Export Citation Format

Share Document