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1.
Parasit Vectors ; 16(1): 303, 2023 Aug 29.
Article in English | MEDLINE | ID: mdl-37644584

ABSTRACT

BACKGROUND: The successful use of semiochemicals to attract insects to traps is based on research on the most suitable compounds and their release profiles over time. Based on the group's promising results, matrices with a more adequate release profile and more eco-friendly properties for the release of 1-hexanol were developed. To use a more suitable prototype in the field, the most promising systems were added to a capsule and evaluated in a wind tunnel. Behavioral experiments were performed using the sand fly species, Lutzomyia longipalpis, to evaluate the efficacy of the proposed system. METHODS: Different delivery systems were developed by varying the polymer (gellan gum and pectin) ratio, crosslinker (aluminum chloride) concentration, and glutaraldehyde removal.The delivery systems were loaded with 1-hexanol, and their release profiles were evaluated using gravimetric analysis under ambient and high-humidity conditions. When the matrix system was placed inside a plastic container, modulations in the active release profile were observed and the system could be reused. Actid attraction behaviors of the sand fly species, Lu. longipalpis, were evaluated in a wind tunnel when exposed to 1-hexanol-loaded release systems at different times. RESULTS: Among the four formulations evaluated, System 2 (gellan gum and pectin in a 1:1 ratio with 5% aluminum chloride) exhibited the most promising release profile, with greater uniformity and longer compound release time. The maximum 1-hexanol release uniformity was achieved over a longer time, mainly every 24 h, under both ambient and high-humidity conditions. System 2 can be reused at least once with the same structure. The wind tunnel trials exhibited efficient activation and attraction of Lu. longipalpis to 1-hexanol after 24, 48, and 72 h in System 2 placed inside the capsules. CONCLUSIONS: The polymeric matrix supplemented with 1-hexanol and introduced in plastic capsules showed promising results in attracting sand flies. This system can be used as a solution for other attractive compounds as well as in other applications where their release needs to be controlled or prolonged.


Subject(s)
Phlebotomus , Psychodidae , Animals , Aluminum Chloride , Capsules , Polymers , Plastics , Pectins
2.
Int J Pharm ; 635: 122792, 2023 Mar 25.
Article in English | MEDLINE | ID: mdl-36863543

ABSTRACT

Lipid core nanocapsules (NCs) coated with multiple polymer layers were rationally designed as a potential approach for the colonic delivery of camptothecin (CPT). Chitosan (CS), hyaluronic acid (HA) and hypromellose phthalate (HP) were selected as coating materials, to modulate the mucoadhesive and permeability properties of CPT regarding the improvement of local and targeted action in the colon cancer cells. NCs were prepared by emulsification/solvent evaporation method and coated with multiple polymer layers by polyelectrolyte complexation technique. NCs exhibited spherical shape, negative zeta potential, and size ranged from 184 to 252 nm. The high efficiency of CPT incorporation (>94%) was evidenced. The ex vivo permeation assay showed that nanoencapsulation reduced the permeation rate of CPT through the intestinal mucosa by up to 3.5 times, and coating with HA and HP reduced the permeation percentage by 2 times when compared to NCs coated only with CS. The mucoadhesive capacity of NCs was demonstrated in gastric and enteric pH. Nanoencapsulation did not reduce the antiangiogenic activity of CPT and, additionally, it was observed that nanoencapsulation resulted in localized antiangiogenic action of CPT.


Subject(s)
Chitosan , Nanocapsules , Nanocapsules/chemistry , Polymers/chemistry , Chitosan/chemistry , Camptothecin/pharmacology , Camptothecin/chemistry , Lipids/chemistry
3.
Pharm Dev Technol ; 27(5): 615-624, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35786299

ABSTRACT

Zidovudine (AZT) has been widely used alone or in combination with other antiretroviral drugs for the treatment of human immunodeficiency virus. Its erratic oral bioavailability necessitates frequent administration of high doses, resulting in severe side effects. In this study, the design of mucoadhesive solid dispersions (SDs) based on chitosan (CS) and hypromellose phthalate (HP) was rationalized as a potential approach to modulate AZT physicochemical and pharmaceutical properties. SDs were prepared at different drug:polymer ratios, using an eco-friendly technique, which avoids the use of organic solvents. Particles with diameter from 56 to 73 µm and negative zeta potentials (-27 to -32 mV) were successfully prepared, achieving high drug content. Infrared spectroscopy revealed interactions between polymers but no interactions between the polymers and AZT. Calorimetry and X-ray diffraction analyses showed that AZT was amorphized into the SDs. The mucoadhesive properties of SDs were evidenced, and the control of AZT release rates from the matrix was achieved, mainly in acid media. The simple, low-cost, and scalable technology proposed for production of SDs as a carrier platform for AZT is an innovative approach, and it proved to be a feasible strategy for modulation the physico-chemical, mucoadhesive, and release properties of the drug.


Subject(s)
Chitosan , Chitosan/chemistry , Drug Carriers/chemistry , Humans , Hypromellose Derivatives , Methylcellulose/analogs & derivatives , Polymers/chemistry , Solubility , Zidovudine/chemistry
4.
Int J Pharm ; 603: 120714, 2021 Jun 15.
Article in English | MEDLINE | ID: mdl-34015380

ABSTRACT

Mutations on the epidermal growth factor receptor (EGFR), induction of angiogenesis, and reprogramming cellular energetics are all biological features acquired by tumor cells during tumor development, and also known as the hallmarks of cancer. Targeted therapies that combine drugs that are capable of acting against such concepts are of great interest, since they can potentially improve the therapeutic efficacy of treatments of complex pathologies, such as glioblastoma (GBM). However, the anatomical location and biological behavior of this neoplasm imposes great challenges for targeted therapies. A novel strategy that combines alpha-cyano-4-hydroxycinnamic acid (CHC) with the monoclonal antibody cetuximab (CTX), both carried onto a nanotechnology-based delivery system, is herein proposed for GBM treatment via nose-to-brain delivery. The biological performance of Poly (D,L-lactic-co-glycolic acid)/chitosan nanoparticles (NP), loaded with CHC, and conjugated with CTX by covalent bonds (conjugated NP) were extensively investigated. The NP platforms were able to control CHC release, indicating that drug release was driven by the Weibull model. An ex vivo study with nasal porcine mucosa demonstrated the capability of these systems to promote CHC and CTX permeation. Blot analysis confirmed that CTX, covalently associated to NP, impairs EGRF activation. The chicken chorioallantoic membrane assay demonstrated a trend of tumor reduction when conjugated NP were employed. Finally, images acquired by fluorescence tomography evidenced that the developed nanoplatform was effective in enabling nose-to-brain transport upon nasal administration. In conclusion, the developed delivery system exhibited suitability as an effective novel co-delivery approaches for GBM treatment upon intranasal administration.


Subject(s)
Glioblastoma , Nanoparticles , Pharmaceutical Preparations , Administration, Intranasal , Animals , Brain , Cell Line, Tumor , Drug Delivery Systems , Glioblastoma/drug therapy , Swine
5.
Pharmaceutics ; 13(3)2021 Mar 19.
Article in English | MEDLINE | ID: mdl-33808670

ABSTRACT

Polymer blends of gellan gum (GG)/retrograded starch(RS) and GG/pectin (P) were cross-linked with calcium, aluminum, or both to prepare mucoadhesive microparticles as oral carriers of drugs or nano systems. Cross-linking with different cations promoted different effects on each blend, which can potentially be explored as novel strategies for modulating physical-chemical and mucoadhesive properties of microparticles. Particles exhibited spherical shapes, diameters from 888 to 1764 µm, and span index values lower than 0.5. Blends of GG:P cross-linked with aluminum resulted in smaller particles than those obtained by calcium cross-linking. GG:RS particles exhibited larger sizes, but cross-linking this blend with calcium promoted diameter reduction. The uptake rates of acid medium were lower than phosphate buffer (pH 6.8), especially GG:RS based particles cross-linked with calcium. On the other hand, particles based on GG:P cross-linked with calcium absorbed the highest volume of acid medium. The percentage of systems erosion was higher in acid medium, but apparently occurred in the outermost layer of the particle. In pH 6.8, erosion was lower, but caused expressive swelling of the matrixes. Calcium cross-linking of GG:RS promoted a significantly reduction on enzymatic degradation at both pH 1.2 and 6.8, which is a promising feature that can provide drug protection against premature degradation in the stomach. In contrast, GG:P microparticles cross-linked with calcium suffered high degradation at both pH values, an advantageous feature for quickly releasing drugs at different sites of the gastrointestinal tract. The high mucoadhesive ability of the microparticles was evidenced at both pH values, and the Freundlich parameters indicated stronger particle-mucin interactions at pH 6.8.

6.
Carbohydr Polym ; 256: 117504, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33483027

ABSTRACT

Oral administration of insulin (INS) would represent a revolution in the treatment of diabetes, considering that this route mimics the physiological dynamics of endogenous INS. Nano- and microencapsulation exploiting the advantageous polysaccharides properties has been considered an important technological strategy to protect INS against harsh conditions of gastrointestinal tract, in the same time that improve the permeability via transcellular and/or paracellular pathways, safety and in some cases even selectivity for targeting delivery of INS. In fact, some polysaccharides also give to the systems functional properties such as pH-responsiveness, mucoadhesiveness under specific physiological conditions and increased intestinal permeability. In general, all polysaccharides can be functionalized with specific molecules becoming more selective to the cells to which INS is delivered. The present review highlights the advances in the past 10 years on micro- and nanoencapsulation of INS exploiting the unique natural properties of polysaccharides, including chitosan, starch, alginate, pectin, and dextran, among others.


Subject(s)
Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus/drug therapy , Drug Delivery Systems/methods , Hypoglycemic Agents/pharmacokinetics , Insulin/pharmacokinetics , Nanoparticles/chemistry , Administration, Oral , Alginates/chemistry , Animals , Chitosan/chemistry , Dextrans/chemistry , Diabetes Mellitus/metabolism , Diabetes Mellitus/pathology , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Drug Compounding/methods , Drug Liberation , Humans , Hypoglycemic Agents/metabolism , Insulin/metabolism , Intestinal Mucosa/metabolism , Nanoparticles/administration & dosage , Pectins/chemistry , Permeability , Starch/chemistry
7.
Carbohydr Polym ; 254: 117444, 2021 Feb 15.
Article in English | MEDLINE | ID: mdl-33357914

ABSTRACT

Nanostructured polyelectrolyte complexes (nano PECs) based on biopolymers are an important technological strategy to target drugs to the action and/or absorption site in a more effective way. In this work, computational studies were performed to predict the ionization, spatial arrangement and interaction energies of chitosan (CS), hyaluronic acid (HA), and hypromellose phthalate (HP), for the design of nano PEC carriers for methotrexate (MTX). The optimal pH range (5.0-5.5) for preparing nano PECs was selected by experimental and computational methodologies, favoring the polymers interactions. CS, HA, HP and MTX addition order was also rationalized, maximizing their interactions and MTX entrapment. Spherical nano-sized particles (256-575 nm, by dynamic light scattering measurement) with positive surface charge (+25.5 to +29.2 mV) were successfully prepared. The MTX association efficiency ranged from 20 to 32 %. XRD analyses evidenced the formation of a new material with an organized structure, in relation to raw polymers.


Subject(s)
Antimetabolites, Antineoplastic/chemistry , Chitosan/chemistry , Drug Carriers , Hyaluronic Acid/chemistry , Methotrexate/chemistry , Methylcellulose/analogs & derivatives , Nanostructures/chemistry , Drug Compounding/methods , Humans , Hydrogen-Ion Concentration , Methylcellulose/chemistry , Nanostructures/ultrastructure , Particle Size , Polyelectrolytes/chemistry , Solutions , Static Electricity , Thermodynamics
8.
Carbohydr Polym ; 250: 116968, 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-33049864

ABSTRACT

Chitosan-based particles are widely proposed as biocompatible drug delivery systems with mucoadhesive and permeation enhancing properties. However, strategies on how to modulate the intended biological responses are still scarce. Considering that particle properties affect the biological outcome, the rational design of the synthesis variables should be proposed to engineer drug delivery systems with improved biological performance. The purpose of this review is to establish a deeper understanding of possible correlations between these variables and the particle properties from theoretical and experimental perspectives. The fundamental physicochemical knowledge of chitosan-based polyelectrolyte complexation and surface modification is discussed focusing on chitosan-TPP, polyelectrolyte complexes, and chitosan-surface modified PLGA or lipid particles. A set of design considerations is proposed to enable future investigation in the development of chitosan particles with modulated properties. The approach presented here contributes to the rational design of chitosan-based particles that meet different requirements for biological activities.


Subject(s)
Chitosan/chemistry , Drug Delivery Systems , Nanoparticles/administration & dosage , Polyelectrolytes/chemistry , Nanoparticles/chemistry
9.
Drug Deliv Transl Res ; 10(6): 1729-1747, 2020 12.
Article in English | MEDLINE | ID: mdl-32683647

ABSTRACT

Nose-to-brain delivery is a promising approach to target drugs into the brain, avoiding the blood-brain barrier and other drawbacks related to systemic absorption, and enabling an effective and safer treatment of diseases such as glioblastoma (GBM). Innovative materials and technologies that improve residence time in the nasal cavity and modulate biological interactions represent a great advance in this field. Mucoadhesive nanoparticles (NPs) based on poly(lactic-co-glycolic acid) (PLGA) and oligomeric chitosan (OCS) were designed as a rational strategy and potential platform to co-deliver alpha-cyano-4-hydroxycinnamic acid (CHC) and the monoclonal antibody cetuximab (CTX) into the brain, by nasal administration. The influence of formulation and process variables (O/Aq volume ratio, Pluronic concentration, PLGA concentration, and sonication time) on the properties of CHC-loaded NPs (size, zeta potential, PDI and entrapment efficiency) was investigated by a two-level full factorial design (24). Round, stable nano-sized particles (213-875 nm) with high positive surface charge (+ 33.2 to + 58.9 mV) and entrapment efficiency (75.69 to 93.23%) were produced by the emulsification/evaporation technique. Optimal process conditions were rationally selected based on a set of critical NP attributes (258 nm, + 37 mV, and 88% EE) for further conjugation with CTX. The high cytotoxicity of CHC-loaded NPs and conjugated NPs was evidenced for different glioma cell lines (U251 and SW1088). A chicken chorioallantoic membrane assay highlighted the expressive antiangiogenic activity of CHC-loaded NPs, which was enhanced for conjugated NPs. The findings of this work demonstrated the potential of this nanostructured polymeric platform to become a novel therapeutic alternative for GBM treatment. Graphical abstract.


Subject(s)
Brain , Chitosan , Glioblastoma , Nanoparticles , Administration, Intranasal , Brain/drug effects , Brain/metabolism , Cell Line, Tumor , Chitosan/therapeutic use , Glioblastoma/drug therapy , Humans , Polylactic Acid-Polyglycolic Acid Copolymer
10.
Int J Biol Macromol ; 149: 234-245, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-31982533

ABSTRACT

The design of mucoadhesive drug delivery systems (DDS) based on polysaccharides at nanoscale or microscale is a relevant technological strategy for the mucosal delivery of several drugs. Findings about the potential mucoadhesive ability of these materials and the mechanisms that drive such interactions represents an important advance for the rational modulation of these properties, according to specific uses. The potential mucoadhesive abilities of gellan gum (GG) and retrograded starch (RS) were investigated at pH 1.2 and 6.8, which were considered biorrelevant for the gastrointestinal tract (GIT). The effects of these polysaccharides on the MUC rheology were also addressed. Rheological studies revealed high MUC-GG interactions at both pH values (1.2 and 6.8), expressing a high mucoadhesive ability, mainly in acidic media. MUC-GG interactions were driven, mainly, by hydrogen bonds. At an acidic pH, significant changes occurred in the MUC arrangements due to the strong MUC-GG interactions, as corroborated by scanning electron microscopy (SEM). The rheological behavior of MUC-RS indicated poor interactions between them and MUC arrangements were more preserved as evidenced by SEM. The results of this work indicated that the mixing of GG and RS can be a promising strategy to modulate mucoadhesiveness of DDS, according to specific therapeutic needs.


Subject(s)
Mucins/chemistry , Polysaccharides, Bacterial/chemistry , Polysaccharides/chemistry , Starch/chemistry , Cell Adhesion/drug effects , Drug Delivery Systems , Humans , Hydrogen Bonding , Hydrogen-Ion Concentration , Microscopy, Electron, Scanning , Mucous Membrane/chemistry , Rheology
11.
Drug Dev Ind Pharm ; 46(2): 236-245, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31928345

ABSTRACT

Nanoparticles based on gellan gum/pectin blends were designed for colon-targeted release of resveratrol (RES). Their impact on drug release rates and permeability were evaluated using Caco-2 cell model and mucus secreting triple co-culture model. Polymeric nanoparticles (PNP) were successfully prepared by nebulization/ionotropic gelation, achieving high drug loading (>80%). PNP were spherical with a low positive charge density (+5mV) and exhibited diameters of around 330 nm. Developed PNP were able to promote effective modulation of drug release rates, so that only 3% of RES was released in acidic media over 2 h, and, in pH 6.8, the drug was released in a sustained manner, reaching 85% in 30 h. The permeability of RES-loaded PNP in the Caco-2 model was 0.15%, while in the triple co-culture model, in the presence of mucus, it reached 5.5%. The everted gut sac experiment corroborated the low permeability of RES-loaded PNP in the presence or absence of mucus and highlighted their high ability to interact with the intestinal tissue. Results indicate that the novel PNP developed in this work are safe and promising carriers for controlled delivery of RES at the colon.


Subject(s)
Colon/drug effects , Nanoparticles/administration & dosage , Nanoparticles/chemistry , Pectins/chemistry , Polysaccharides, Bacterial/chemistry , Resveratrol/administration & dosage , Resveratrol/chemistry , Administration, Oral , Animals , Caco-2 Cells , Cell Line, Tumor , Drug Carriers/chemistry , Drug Liberation , HT29 Cells , Humans , Hydrogen-Ion Concentration , Intestinal Mucosa/metabolism , Male , Mucus/metabolism , Particle Size , Permeability/drug effects , Rats , Rats, Wistar
12.
Pharm Dev Technol ; 25(2): 159-167, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31623500

ABSTRACT

Films of gellan gum:pectin blends were prepared by solvent casting method. Gellan gum:pectin mass ratios were varied (4:1; 1:1; 1:4) at different concentrations (3% or 4%) and glycerol was used as plasticizer (1 or 2%). The films were thin (18-30 µm), translucent, flexible, and homogeneous. The surface pH was suitable for buccal application. All films reached high mechanical resistance and the mucoadhesive ability of them was evidenced. High ratio of gellan gum improved the mechanical resistance and the mucoadhesion of the films as well as the control of drug release rates. The films did not disintegrate in simulate saliva up to 24 h and curcumin release could be sustained up to 12 h. The set of data evidence that the films designed in this work represent a potential platform for buccal drug delivery.


Subject(s)
Pectins/chemistry , Polysaccharides, Bacterial/chemistry , Administration, Buccal , Curcumin/administration & dosage , Curcumin/chemistry , Delayed-Action Preparations/chemistry , Drug Delivery Systems/methods , Drug Liberation/drug effects , Mouth/drug effects , Mouth Mucosa/drug effects , Plasticizers/chemistry
13.
J Pharm Sci ; 108(4): 1559-1568, 2019 04.
Article in English | MEDLINE | ID: mdl-30513320

ABSTRACT

Alginate-based polyelectrolyte complexes (PECs) and hydrogel were engineered as platforms for local bevacizumab (BVZ) therapy. This study provides deep comprehension on the microstructures of such systems, and their correlation with drug-release patterns. PECs and hydrogel were characterized using Fourier transform infrared spectroscopy, small-angle X-ray scattering, scanning electron microscopy, atomic force microscopy, and porosimetry. Structural investigations indicated that PECs are formed by supramolecular interactions, resulting in physically cross-linked polymer networks, whereas the BVZ-loaded hydrogel has a more compact and rigid structure, promoting better entrapment of BVZ. PECs and hydrogel were able to control the BVZ release for 4 and 8 days, respectively. Their release profiles correlated best with the Higuchi and Korsmeyer-Peppas models, respectively, indicating drug diffusion as the limiting step for drug release. Furthermore, BVZ remained biologically active in vitro after its incorporation into the hydrogel system. Together, these studies confirm that PECs and hydrogel exhibit different porous structures and physicochemical properties, making them promising platforms that allow the modulation of BVZ release meeting different requirements.


Subject(s)
Alginates/chemistry , Angiogenesis Inhibitors/administration & dosage , Bevacizumab/administration & dosage , Drug Carriers/chemistry , Angiogenesis Inhibitors/pharmacokinetics , Bevacizumab/pharmacokinetics , Drug Liberation , Human Umbilical Vein Endothelial Cells , Humans , Hydrogels/chemistry , Hydrogen-Ion Concentration , Polyelectrolytes/chemistry , Porosity , Recombinant Proteins/metabolism , Vascular Endothelial Growth Factor A/antagonists & inhibitors
14.
Eur J Pharm Sci ; 111: 73-82, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-28962855

ABSTRACT

Nanostructured polyelectrolytes complexes (nano PECs) loaded with methotrexate (MTX) were obtained by the polyelectrolyte complexation of chitosan (CS) and hyaluronic acid (HA), further incorporating hypromellose phthalate (HP). The mean diameter of nano PECs ranged from 325 to 458nm, with a narrow size distribution. Zeta potential was close to +30mV, decreasing to +21mV after the incorporation of HP, a range of values that favour the physical stability of system as the interaction with cationic biological membranes. The electrostatic interactions between the different components were indicated by the FTIR data. The mucoadhesiveness of nano PECs was demonstrated and MTX and HP influenced this property. The cell viability assays showed the biosafety of the isolated polymers and nano PECs in intestinal HT29-MTX and Caco-2 cell lines at 4h of test. The permeability values of MTX loaded in CS/HA nano PECs were 7.6 and 4-fold higher than those of CS/HA/HP nano PECS and free drug, respectively, in the Caco-2 monoculture. In mucus secreting co-culture cell model these values were 3 and 6.5 fold, respectively. Such features indicate that nano PECs developed in this work can be promising carriers for MTX in the treatment of local or systemic diseases.


Subject(s)
Drug Carriers/pharmacology , Intestinal Mucosa/metabolism , Methotrexate/administration & dosage , Nanostructures/chemistry , Polyelectrolytes/pharmacology , Caco-2 Cells , Cell Culture Techniques , Cell Survival/drug effects , Drug Carriers/chemistry , Drug Carriers/toxicity , HT29 Cells , Humans , Intestinal Mucosa/drug effects , Methotrexate/pharmacokinetics , Nanostructures/toxicity , Permeability , Polyelectrolytes/chemistry , Polyelectrolytes/toxicity
15.
Polymers (Basel) ; 10(1)2018 Jan 08.
Article in English | MEDLINE | ID: mdl-30966087

ABSTRACT

This work addresses the establishment and characterization of gellan gum:pectin (GG:P) biodegradable mucoadhesive beads intended for the colon-targeted delivery of resveratrol (RES). The impact of the polymer carrier system on the cytotoxicity and permeability of RES was evaluated. Beads of circular shape (circularity index of 0.81) with an average diameter of 914 µm, Span index of 0.29, and RES entrapment efficiency of 76% were developed. In vitro drug release demonstrated that beads were able to reduce release rates in gastric media and control release for up to 48 h at an intestinal pH of 6.8. Weibull's model correlated better with release data and b parameter (0.79) indicated that the release process was driven by a combination of Fickian diffusion and Case II transport, indicating that both diffusion and swelling/polymer chains relaxation are processes that contribute equally to control drug release rates. Beads and isolated polymers were observed to be safe for Caco-2 and HT29-MTX intestinal cell lines. RES encapsulation into the beads allowed for an expressive reduction of drug permeation in an in vitro triple intestinal model. This feature, associated with low RES release rates in acidic media, can favor targeted drug delivery from the beads in the colon, a promising behavior to improve the local activity of RES.

16.
Eur J Pharm Biopharm ; 123: 84-94, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29175551

ABSTRACT

Gellan gum microparticles coated with colon-specific films based on retrograded starch and pectin was developed for enhancing the oral release of insulin (INS). The system developed promoted an impressive protection of INS (80%) after 120 min of incubation with trypsin and alpha-chymotrypsin, while only 3% of free INS remained intact after the same time, possibility due to the calcium chelating activity of the polymers in inhibiting the proteolytic activity. In vitro INS release in media simulating the gastrointestinal portions revealed a pH-dependent behavior, as well as the significance of the coating in lowering the release rates in relation to their counterparts. The permeability of INS on Caco-2 cells monolayers and excised rat intestine were significantly improved, mainly due to the influence of the anionic polymers on tight junctions opening, along with the excellent mucoadhesive properties of the gellan gum. All these features together contributed greatly to the hypoglycemic effect observed after the oral administration of the INS-loaded MP in diabetic rats, with reduction of up to 51% of blood glucose levels. The important findings of this work should contribute to the advances about the search of alternatives for oral administration of INS.


Subject(s)
Insulin/administration & dosage , Insulin/chemistry , Pectins/chemistry , Permeability/drug effects , Polysaccharides, Bacterial/chemistry , Starch/chemistry , Administration, Oral , Animals , Caco-2 Cells , Cell Line, Tumor , Chymotrypsin/chemistry , Diabetes Mellitus, Experimental/drug therapy , Drug Carriers/chemistry , Drug Delivery Systems/methods , Humans , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/chemistry , Male , Rats , Rats, Wistar
17.
Carbohydr Polym ; 179: 126-134, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-29111035

ABSTRACT

Bacterial cellulose/carboxymethylcelullose (BC/CMC) biocomposites with different DS-CMC (DS from 0.7 to 1.2) were developed in order to evaluate their impact as a drug delivery system. Biocomposites were loaded with methotrexate (MTX) as an alternative for the topical treatment of psoriasis. Scanning electron microscopy and atomic force microscopy showed that the CMC coated the cellulose nanofibers, leading to the decrease of the elastic modulus as the DS of CMC increased. BC/CMC0.9 exhibited the lower liquid uptake (up to 11 times lower), suggesting that the more linear structure of the intermediate substitute CMC grade (0.9) was able to interact more strongly with BC, resulting in a denser structure. All samples showed a typical burst release effect in the first 15min of test, however the BC/CMC0.9 biocomposite promoted a slight lowering of MTX release rates, suggesting that the DS of CMC can be considered the key factor to modulate the BC properties.


Subject(s)
Biocompatible Materials/chemistry , Carboxymethylcellulose Sodium/chemistry , Dermatologic Agents/chemistry , Drug Liberation , Gluconacetobacter xylinus/metabolism , Methotrexate/chemistry , Nanofibers/chemistry , Culture Media/chemistry , Drug Delivery Systems , Elastic Modulus , Gluconacetobacter xylinus/growth & development , Porosity , Solubility , Tissue Engineering
18.
Colloids Surf B Biointerfaces ; 152: 220-228, 2017 Apr 01.
Article in English | MEDLINE | ID: mdl-28113124

ABSTRACT

The aim of the present study was to investigate the potential application of 3,6-O,O'- dimyristoyl chitosan DMCh, an amphiphilic derivative of chitosan, for improving the oral bioavailability of paclitaxel (PTX), a water insoluble anticancer drug. The O-acylation of chitosan with myristoyl chloride was carried out by employing high (≈13.3) or low (2.0) molar excess of chitosan to result in samples DMCh07 and DMCh12, respectively. The successful O-acylation of chitosan was confirmed by FTIR and 1H NMR spectroscopy, the latter allowing also the determination of average degree of substitution (DS). The critical aggregation concentration (CAC) of samples DMCh07 (DS≈6.8%) and DMCh12 (DS≈12.0%) were 8.9×10-3mg/mL and 13.2×103mg/mL, respectively. It was observed by TEM that the DMCh micelles showed spherical shape while DLS measurements allowed the determination of their average size (287nm-490nm) and zeta potential (+32mV to +44mV). Such DMCh micelles were able to encapsulate paclitaxel with high drug encapsulation efficiency (EE), as confirmed by HPLC analyses. Studies on the cytotoxicity of DMCh07 micelles toward Caco-2 and HT29-MTX cells showed that, regardless the PTX loaded, DMCh07 micelles slightly decreased cellular viability at low micelles concentration (≤1µg/mL) while at high concentration (>10µg/mL) PTX-loaded DMCh07 micelles were less toxic toward Caco-2 cells when compared to free PTX. The PTX permeation across Caco-2 monoculture and Caco-2/HT29-MTX co-culture model confirmed the potential of DMCh micelles in improving the intestinal absorption of PTX. These results suggest that DMCh micelles may be a promising carrier to encapsulate PTX aiming cancer therapy.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacokinetics , Chitosan/chemistry , Drug Carriers/chemistry , Micelles , Paclitaxel/pharmacokinetics , Administration, Oral , Antineoplastic Agents, Phytogenic/pharmacology , Caco-2 Cells , Cell Survival/drug effects , Drug Delivery Systems/methods , HT29 Cells , Humans , Magnetic Resonance Spectroscopy , Paclitaxel/pharmacology , Spectroscopy, Fourier Transform Infrared
19.
Carbohydr Polym ; 157: 1013-1023, 2017 Feb 10.
Article in English | MEDLINE | ID: mdl-27987801

ABSTRACT

Although resistant starch/pectin (RS/P) films have previously displayed suitable properties for colon-specific drug delivery, nanocomposite films were developed aiming to enhance physicochemical, thermal, mechanical and barrier properties, as well as the low oral bioavailability of methotrexate (MTX). FEG-SEM micrographs of nanocomposite films showed different interaction patterns occurring among nanocellulose and RS/P. The nanofiller addition led to an increase in the thermal stability, probably due to its interaction with RS crystalline double helices. Results also displayed an improvement of the puncture strength, while barrier properties revealed a low water vapor permeability. Ex vivo bioadhesion test displayed the nanocomposites films to interact strongly with porcine gastrointestinal mucosa. In vitro drug release studies showed that the films developed enhanced the drug dissolution rates with approximately 80% of MTX release in 150min, suggesting the potential of these materials as a poor solubility drugs carrier, which constitutes an important tool for enhancing oral bioavailability.


Subject(s)
Drug Carriers/chemistry , Methotrexate/administration & dosage , Nanocomposites , Pectins/chemistry , Starch/chemistry , Animals , Drug Liberation , Intestinal Mucosa/drug effects , Permeability , Solubility , Swine
20.
J Mech Behav Biomed Mater ; 65: 317-333, 2017 01.
Article in English | MEDLINE | ID: mdl-27631170

ABSTRACT

The retrogradation of high amylose starch (5% or 10%), by isothermal cycles at 4°C (method 1) or by alternating thermal cycles (method 2) was efficient and promoted important structural modifications. Hydrogels of gellan gum and starch retrograded blends, containing or not ketoprofen, were prepared by ionic and dual cross-linking, at different concentrations of polymer and cross-linkers, and characterized by texture and rheological analysis, X-ray diffraction and morphological analysis. The ionic cross-linking and starch retrograded by method 1 contributed to the improvement of hardness and cohesiveness of hydrogels while the dual cross-linking and starch retrograded by method 2 favored the adhesiveness. The rising of polymer concentration lead to the improvement of all mechanical parameters. Rheological data demonstrated that non-cross-linked dispersions showed a behavior of weak gels and the cross-linked hydrogels presented a predominantly elastic behavior (G'≫G″), peculiar of strong gels. X-ray diffraction, rheological data and the scanning electron microscopy (FEG-SEM) revealed that the increase of polymers and cross-linkers concentration and the presence of drug resulted in stronger and more stable tridimensional structures. The suitable adhesiveness and high strength and elasticity of hydrogels H253IC-KT, H255IC-KT, H21053DC-KT and H21055DC-KT make them more promising materials for the design of mucoadhesive drug delivery systems.


Subject(s)
Drug Delivery Systems , Hydrogels/chemistry , Polysaccharides, Bacterial/chemistry , Starch/chemistry , Rheology
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