载紫杉醇聚乳酸-羟基乙酸纳米粒的体外释药研究

以生物可降解材料聚乳酸-羟基乙酸(PLGA)为载体制备了载紫杉醇纳米粒,重点考察了纳米粒的体外释放特性.采用乳化-溶剂挥发法制备了载紫杉醇PLGA纳米粒,其平均粒径为200nm,载药量为21%,包封率为89.44%;体外释药符合Higuchi方程:Q=3.8796t1/2+30.4649(r=0.9397),同时载紫杉醇纳米粒具有一定的缓释作用.     

Preparation and Optimization of Dry PLGA Nanoparticles by Spray Drying Technique

The aim of this article was to evaluate the potential of poly lactide-coglycolide (PLGA) nanoparticles (NPs) as carriers for controlling release of doxorubicin (DOX) via a spray drying technique. The challenge was to entrap a hydrophilic molecule into a lipophilic core molecule of PLGA. To achieve this objective, we modified conventional approach of drug loading to spray drying technique. The eight formulations of nanoparticles were prepared by modified double emulsion and solvent evaporation technique followed by spray drying using 2³ factorial designs. PLGA (A) and PVA (B) and stirring speed (C) were used as independent variables where particle size (Y₁), entrapment efficiency (Y₂) and percentage of drug release at the 32 hour (Y₃) were taken as dependant variables. The results showed that the method is easy and efficient for the entrapment of the drug as well as the formation of spherical nanoparticles. This modification improved DOX entrapment efficiency relative to controls real loadings up to 40%. The in vitro release studies indicated the DOX loaded PLGA nanoparticles provide controlled drug release over a period of 32 h. Hence, this investigation demonstrated the potential of the experimental design in understanding the effect of the formulation variables on the quality of DOX-PLGA nanoparticles.     

PLGA／TPGS-姜黄素纳米粒的制备及体外评价

以维生素E1000聚乙二醇琥珀酸酯（TPGS）为乳化剂,姜黄素为模型药物,聚乳酸-羟基乙酸为载体材料,采用O／W型乳化-溶剂挥发法制备聚乳酸-羟基乙酸-姜黄素纳米粒,以包封率和载药量为主要指标,单因素实验探索影响两指标的主要因素,正交试验设计优化制备工艺,结果表明,制备聚乳酸-羟基乙酸-姜黄素纳米粒的最佳工艺为：聚合物浓度4％,乳化剂TPGS浓度0．03％,超声时间8min,搅拌时间6h。以此工艺制备的载药纳米粒外形圆整光滑,粒度分布较为均匀,平均粒径为189．7nm,包封率为86．2％,载药量为7．45％。     

Nanoparticles with entrapped α-tocopherol: synthesis, characterization, and controlled release

An emulsion evaporation method was used to synthesize spherical poly(DL-lactide-co-glycolide) (PLGA) nanoparticles with entrapped α-tocopherol. Two different surfactants were used: sodium dodecyl sulfate (SDS) and poly(vinyl alcohol) (PVA). For SDS nanoparticles, the size of the nanoparticles decreased significantly with the entrapment of α-tocopherol in the PLGA matrix, while the size of PVA nanoparticles remained unchanged. The polydispersity index after synthesis was under 0.100 for PVA nanoparticles and around 0.150 for SDS nanoparticles. The zeta potential was negative for all PVA nanoparticles. The entrapment efficiency of α-tocopherol in the polymeric matrix was approximately 89% and 95% for nanoparticles with 8% and 16% α-tocopherol theoretical loading, respectively. The residual PVA associated with the nanoparticles after purification was approximately 6% ( w/w relative to the nanoparticles). The release profile showed an initial burst followed by a slower release of the α-tocopherol entrapped inside the PLGA matrix. The release for nanoparticles with 8% α-tocopherol theoretical loading (86% released in the first hour) was faster than the release for the nanoparticles with 16% α-tocopherol theoretical loading (34% released in the first hour).     

Enhanced efficacy of clindamycin hydrochloride encapsulated in PLA/PLGA based nanoparticle system for oral delivery

Clindamycin hydrochloride (CLH) is a clinically important oral antibiotic with wide spectrum of antimicrobial activity that includes gram‐positive aerobes (staphylococci, streptococci etc.), most anaerobic bacteria, Chlamydia and certain protozoa. The current study was focused to develop a stabilised clindamycin encapsulated poly lactic acid (PLA)/poly (D,L‐lactide‐co‐glycolide) (PLGA) nano‐formulation with better drug bioavailability at molecular level. Various nanoparticle (NPs) formulations of PLA and PLGA loaded with CLH were prepared by solvent evaporation method varying drug: polymer concentration (1:20, 1:10 and 1:5) and characterised (size, encapsulation efficiency, drug loading, scanning electron microscope, differential scanning calorimetry [DSC] and Fourier transform infrared [FTIR] studies). The ratio 1:10 was found to be optimal for a monodispersed and stable nano formulation for both the polymers. NP formulations demonstrated a significant controlled release profile extended up to 144 h (both CLH‐PLA and CLH‐PLGA). The thermal behaviour (DSC) studies confirmed the molecular dispersion of the drug within the system. The FTIR studies revealed the intactness as well as unaltered structure of drug. The CLH‐PLA NPs showed enhanced antimicrobial activity against two pathogenic bacteria Streptococcus faecalis and Bacillus cereus. The results notably suggest that encapsulation of CLH into PLA/PLGA significantly increases the bioavailability of the drug and due to this enhanced drug activity; it can be widely applied for number of therapies.Inspec keywords: drug delivery systems, biomedical materials, antibacterial activity, nanoparticles, nanomedicine, microorganisms, polymers, nanofabrication, differential scanning calorimetry, encapsulation, drugs, scanning electron microscopy, Fourier transform infrared spectraOther keywords: Streptococcus faecalis, Bacillus cereus, DSC, stable nanoformulation, monodispersed nanoformulation, pathogenic bacteria, FTIR spectra, molecular dispersion, thermal behaviour, controlled release profile, Fourier transform infrared spectra, differential scanning calorimetry, scanning electron microscopy, drug loading, encapsulation efficiency, polymer concentration, solvent evaporation method, molecular level, drug bioavailability, stabilised clindamycin encapsulated poly lactic acid‐poly (D,L‐lactide‐co‐glycolide) nanoformulation, protozoa, Chlamydia, anaerobic bacteria, gram‐positive aerobes, antimicrobial activity, oral antibiotics, oral delivery, PLA‐PLGA based nanoparticle system, clindamycin hydrochloride     

Poly(lactide-co-glycolide)-methoxy-poly(ethylene glycol) nanoparticles: drug loading and release properties

In this work, the drug loading and in vitro release properties of PLGA-mPEG nanoparticles were studied. Three methyl-xanthine derivatives differing significantly in aqueous solubility, i.e., caffeine, theophylline, and theobromine, were employed as model drugs. Two different PLGA-mPEG copolymer compositions, namely PLGA(40)mPEG(5) and PLGA(136)mPEG(5), were included in the study. The nanoparticles were prepared by a double emulsion technique. The drug release properties of the nanoparticles in phosphate buffered saline (PBS) and in human plasma were determined. An increase of the drug proportion in the feed led to increased drug loading. The composition of the PLGA-mPEG copolymer (PLGA/mPEG molar ratio) did not appear to affect drug loading and encapsulation. Caffeine exhibited higher loading in the nanoparticles than theobromine and this exhibited a little higher loading than theophylline. Solid-state solubility of the drug in PLGA-mPEG did not affect drug loading. Drug loading and encapsulation in the PLGA-mPEG nanoparticles appeared to be governed by the partition coefficient of the drug between the organic phase and the external aqueous phase employed in nanoparticle preparation. Relatively low loading and encapsulation values were obtained, suggesting that the physical entrapment of drugs in PLGA-mPEG nanoparticles could only be an option in the development of formulations of potent drugs. Only the release of the least water-soluble theobromine was efficiently sustained by its entrapment in the nanoparticles, indicating that the physical entrapment of drugs provides the means for the development of controlled-release PLGA-mPEG nanoparticulate formulations only in the case of drugs with low aqueous solubility.     

Thermochemotherapy mediated by novel solar-planet structured magnetic nanocomposites for glioma treatment

Cancer comprehensive treatment has been fully recognized as it can provide an effective multimodality approach for fighting cancers. This work evaluates the effects of a kind of novel solar-planet structured magnetic nanocomposites (MNCs) for magnetic thermochemotherapy. Amino silane coated magnetic nanoparticles (MNPs) as agent of magnetic mediated hyperthermia (MMH) for cancer treatment were prepared by the chemical precipitation method. Docetaxel (an anticancer drug) loaded polymeric nanoparticles (DNPs) composed of carboxylic-terminated poly (D,L-lactic-co-glycolic acid) (PLGA) with Vitamin E TPGS as emulsifier for sustained drug release were prepared by a modified solvent extraction/evaporation technique. Furthermore, the MNPs modified with amino groups could be covalently attached to the surface of carboxylic terminated DNPs to form the so-called solar-planet structured MNCs by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) crosslinking. The prepared solar-planet structure has been confirmed by fluorescent observation. Inductive heating property of the nanocomposite was evaluation by monitoring the temperature increase of the MNCs suspension under alternative magnetic field (AMF). Drug encapsulation efficacy and drug release of the magnetic nanocomposite were conducted by high performance liquid chromatography (HPLC). In vitro evaluation of the novel nanocomposite as mediator for thermochemotherapy was conducted on the U251 human glioma cells and the synergistic effect between MMH and docetaxel chemotherapy was confirmed. All the observation supports that solar-planet structured MNC is a novel and effective mediator for magnetic thermochemotherapy. The MNCs can realize cancer comprehensive treatment thus has great potential in clinical application.     

Ultrafine PEG-coated poly(lactic-co-glycolic acid) nanoparticles formulated by hydrophobic surfactant-assisted one-pot synthesis for biomedical applications

A novel method was developed for the one-pot synthesis of ultrafine poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs), using an emulsion solvent evaporation formulation method. Using either cetyltrimethylammonium bromide (CTAB) or poly(ethylene glycol)-distearyl phosphoethanolamine (PEGPE) as an oily emulsifier during the emulsion process, produced PLGA particle sizes of less than 50 nm, constituting a breakthrough in emulsion formulation methods. The yield of ultrafine PLGA NPs increased with PEGPE/PLGA ratio, reaching a plateau at around 85%, when the PEGPE/PLGA ratio reached 3:1. The PEGPE-PLGA NPs exhibited high drug loading content, reduced burst release, good serum stability, and enhanced cell uptake rate compared with traditional PLGA NPs. Sub-50 nm diameter PEG-coated ultrafine PLGA NPs show great potential for in vivo drug delivery systems.     

Release of dexamethasone from PLGA nanoparticles entrapped into dextran/poly(vinyl alcohol) hydrogels

Hydrogels based on blends of poly(vinyl alcohol) (PVA) with dextran were prepared by a physical cross-linking procedure and used as matrices for the entrapment of biodegradable nanoparticles loaded with dexamethasone. The nanoparticles were prepared, by a solvent evaporation technique, using biodegradable copolymers of poly(lactic acid)–poly(glycolic acid) (PLGA). Size, morphology and surface characteristics of the nanoparticles were evaluated by scanning electron microscopy. The mechanism of drug release from the nanoparticles entrapped into the PVA-based matrices was studied and compared to that from free nanoparticles. The effect of dextran on the in vitro release profile of dexamethasone from the hydrogels was investigated. The obtained results indicate that PLGA nanoparticles are able to release dexamethasone following a diffusion-controlled mechanism. The entrapment of the nanoparticles into the hydrogels affects only slightly this mechanism of drug release. In addition, dextran/PVA hydrogels release a higher amount of drug with respect to pure PVA hydrogels and by increasing dextran content in the hydrogels, the amount of drug released increases.     

BSA-PLGA微球的优化制备及特性

目的:优化BSA-PLGA微球制备工艺,并对其包封率、形态、体外释放药物及微球包裹前后BSA的稳定性进行评价。方法:以PLGA为载体,采用复乳溶剂挥发法制备BSA-PLGA微球。Micro BCA法测定微球的包封率和载药量,扫描电子显微镜观察微球的形态,激光粒度仪测定粒度及分布,聚丙烯酰胺凝胶电泳(SDS-PAGE)研究微球包裹前后BSA分子结构的完整性,同时考察体外释药性能。结果:根据优化工艺制备的微球外观圆整,平均粒径(2275.8±256.9)nm,包封率(82.59±2.92)%,载药量(13.76±0.49)×10-2%,包裹前后BSA结构稳定,体外释放28天以上,释放曲线符合Higuchi方程。结论:本研究获得了较优化的BSA-PLGA微球制备工艺,所制备的微球具有较高的包封率和明显的缓释效果。     

5-Fluorouracil encapsulated HA/PLGA composite microspheres for cancer therapy

5-Fluorouracil (5FU) was successfully entrapped within poly(lactide-co-glycolide) (PLGA) and hydroyapatite (HA) composite microspheres using the emulsification/solvent extraction technique. The effects of HA to PLGA ratio, solvent ratio as well as polymer inherent viscosity (IV) on encapsulation efficiency were investigated. The degradation and drug release rates of the microspheres were studied for 5?weeks in vitro in phosphate buffered solution of pH 7.4 at 37?°C. The drug release profile followed a biphasic pattern with a small initial burst followed by a zero-order release for up to 35?days. The initial burst release decreased with increasing HA content. The potential of HA in limiting the initial burst release makes the incorporation of HA into PLGA microspheres advantageous since it reduces the risk of drug overdose from high initial bursts. The linear sustained drug release profile over the course of 5?weeks makes these 5-FU-loaded HA/PLGA composite microparticles a promising delivery system for the controlled release of chemotherapy drugs in the treatment of cancer.     

Effects of poly(lactic-co-glycolic acid) on preparation and characteristics of plasmid DNA-loaded solid lipid nanoparticles

Poly(lactic-co-glycolic acid) (PLGA) was used as a polymeric emulsifier to encapsulate plasmid DNA into hydrogenated castor oil (HCO)-solid lipid nanoparticles (SLN) by w/o/w double emulsion and solvent evaporation techniques. The effects of PLGA on the preparation, characteristics and transfection efficiency of DNA-loaded SLN were studied. The results showed that PLGA was essential to form the primary w/o emulsion and the stability of the emulsion was enhanced with the increase of PLGA content. DNA-loaded SLN were spherical with smooth surfaces. The SLN had a negative charge in weak acid and alkaline environment but acquired a positive charge in acidic pH and the cationisation capacity of the SLN increased with the increase of PLGA/HCO ratio. Agarose gel electrophoresis demonstrated that the majority of the DNA maintained its structural integrity after preparation and being extracted or released from DNA-loaded SLN. When PLGA/HCO ratio increased from 5 to 15%, the encapsulation efficiency, loading capacity and transfection efficiency of the nanoparticles increased significantly, whereas the changes of particle size and polydispersity index were insignificant. Cytotoxicity study in cell culture demonstrated that the SLN was not toxic.     

琼脂糖醋酸酯纳米粒子的制备及药物缓释性

通过纳米沉淀法制备了一种粒径均一的琼脂糖醋酸酯纳米粒子,并对影响粒径的相关因素进行了研究。结果表明,纳米粒子分别随着二甲基亚砜(DMSO)与水的比率、姜黄素含量及琼脂糖醋酸酯(AA)的浓度的增加而增大,随转速的增加而下降,异丙醇和聚乙烯醇(PVA)浓度也有一定的影响。同时研究了载体对姜黄素的包载情况及缓释行为。结果显示,无异丙醇组中姜黄素载药率和包封率均比异丙醇组中的高。但两组都表明,随着姜黄素的含量增加,载药粒子的载药率不断增加,包封率不断降低。载药粒子大大延长了姜黄素的缓释时间。获得的琼脂糖醋酸酯纳米粒子可望用于姜黄素的控释。     

Controlled release of insulin from PLGA nanoparticles embedded within PVA hydrogels

A simple and versatile delivery platform for peptide and protein based on physically cross-linked poly (vinyl alcohol) (PVA) hydrogels containing insulin-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles was successfully fabricated. The particle morphology and size were characterized by SEM and laser light scattering method, respectively. Results showed that these particles had a mean diameter of 615 nm with a narrow size distribution and homogeneous particle production. The protein encapsulation efficiency was 72.6%. When insulin-loaded PLGA nanoparticles were administered intraperitoneally as a single dose (20 U/kg) to streptozotocin-induced diabetic mouse, blood glucose levels of these mice decreased and it could be sustained at such levels over 24 h. In vitro release further indicated that entrapment of the nanoparticles into the PVA hydrogels causes a reduction in both the release rate and the total amount of insulin released, which suggesting that PLGA nanoparticles entrapped into the PVA hydrogels showed more suitable controlled release kinetics for protein delivery.     

Experimental design and multivariate analysis for optimizing poly(D,L-lactide-co-glycolide) (PLGA) nanoparticle synthesis using molecular micelles

The utility of polymeric nanoparticles as drug delivery systems depends on effective control of synthetic parameters with a significant impact on their physico-chemical characteristics. In this study, a chemometric central composite experimental design (CCD) was used to optimize the synthesis of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles by emulsification solvent evaporation using anionic molecular micelles, such as poly(sodium N-undecylenic sulfate) (poly-SUS), poly(sodium N-undecanoyl-glycinate) (poly-SUG) and poly(sodium N-undecanoyl-L-leucyl-valinate) (poly-L-SULV) as well as conventional emulsifiers, such as anionic sodium dodecyl sulfate (SDS) and non-ionic poly(vinyl alcohol) (PVA). The individual and combined effects of PLGA concentration, emulsifier concentration, homogenization speed, and sonication time (design variables) on particle size and polydispersity index (responses) were investigated using multivariate analysis. The most significant design variables influencing the nanoparticle size and size distribution were PLGA concentration and emulsifier concentration (p < 0.05) in comparison to the other design variables. The quadratic model demonstrated the highest predictive ability when the molecular micelles were used as emulsifiers. The PLGA nanoparticles optimally synthesized according to the CCD were further purified by dialysis and then freeze-dried. Dried nanoparticles synthesized with molecular micelles and PVA were readily re-suspended in water, as compared with SDS for which nanoparticle aggregation occurred. The size of PLGA nanoparticles synthesized using molecular micelles increased after freeze-drying, but remained smaller than 100 nm when poly-L-SULV was used as emulsifier. The PDI values indicated monodisperse nanoparticle suspensions after purification and freeze-drying for all investigated molecular micelles (PDI < 0.100). The nanoparticle suspensions synthesized using molecular micelles were the most stable after dialysis and freeze-drying, having low negative zeta potential values ranging from -54 +/- 1.6 mV for poly-L-SULV to -63.2 +/- 0.4 mV for poly-SUS. Transmission electron microscopy (TEM) micrographs showed spherical shape and smooth surface for the PLGA nanoparticles synthesized using molecular micelles.     

Development of thermosensitive poly(n-isopropylacrylamide-co-((2-dimethylamino) ethyl methacrylate))-based nanoparticles for controlled drug release

Thermosensitive nanoparticles based on poly(N-isopropylacrylamide-co-((2-dimethylamino)ethylmethacrylate)) (poly(NIPA-co-DMAEMA)) copolymers were successfully fabricated by free radical polymerization. The lower critical solution temperature (LCST) of the synthesized nanoparticles was 41?°C and a temperature above which would cause the nanoparticles to undergo a volume phase transition from 140 to 100 nm, which could result in the expulsion of encapsulated drugs. Therefore, we used the poly(NIPA-co-DMAEMA) nanoparticles as a carrier for the controlled release of a hydrophobic anticancer agent, 7-ethyl-10-hydroxy-camptothecin (SN-38). The encapsulation efficiency and loading content of SN-38-loaded nanoparticles at an SN-38/poly(NIPA-co-DMAEMA) ratio of 1/10 (D/P = 1/10) were about 80% and 6.293%, respectively. Moreover, the release profile of SN-38-loaded nanoparticles revealed that the release rate at 42?°C (above LCST) was higher than that at 37?°C (below LCST), which demonstrated that the release of SN-38 could be controlled by increasing the temperature. The cytotoxicity of the SN-38-loaded poly(NIPA-co-DMAEMA) nanoparticles was investigated in human colon cancer cells (HT-29) to compare with the treatment of an anticancer drug, Irinotecan(?) (CPT-11). The antitumor efficacy evaluated in a C26 murine colon tumor model showed that the SN-38-loaded nanoparticles in combination with hyperthermia therapy efficiently suppressed tumor growth. The results indicate that these thermo-responsive nanoparticles are potential carriers for controlled drug delivery.     

Development and in vitro evaluation of surface modified poly(lactide-co-glycolide) nanoparticles with chitosan-4-thiobutylamidine

The objective of this study was to develop a nanoparticulate drug delivery system based on the surface modification of poly(lactide-co-glycolide) (PLGA) nanoparticles with a thiolated chitosan. PLGA nanoparticles were prepared by the emulsification-solvent evaporation method. Immobilization of chitosan to the surface of PLGA nanoparticles via amide bonds was mediated by a carbodiimide. Thiol groups were covalently bound to the chitosan surface of particles by reaction with 2-iminothiolane. Obtained nanoparticles were characterized in vitro regarding size, zeta potential, thiol group content, stability at different pH values, mucoadhesion, and drug release. Results demonstrated that the surface modification of PLGA nanoparticles with thiolated chitosan (chitosan-TBA) leads to nanoparticles of a mean diameter of 889.5 ± 72 nm and positive zeta potential of + 24.74 mV. The modified nanoparticles contained 7.32 ± 0.24 μmol thiol groups per gram nanoparticles. The size of nanoparticles was strongly influenced by the pH of the surrounding medium, being 925.0 ± 76.3 nm at pH 2 and 577.8 ± 66.7 nm at pH 7.4. Thiolated nanoparticles showed a 3.3-fold prolonged residence time on the mucosa and an unchanged release profile in comparison to unmodified PLGA nanoparticles. These data suggest that surface modified chitosan-TBA conjugate PLGA nanoparticles have the potential to be used as mucoadhesive drug delivery system.     

Development of praziquantel-loaded PLGA nanoparticles and evaluation of intestinal permeation by the everted gut sac model

Praziquantel has been shown to be highly effective against all known species of Schistosoma infecting humans. Spherical nanoparticles made of poly(D,L-lactide-co-glycolide) acid with controlled size were designed as drug carriers. Praziquantel, a hydrophobic drug, was entrapped into the polymeric nanoparticles with 30% (w/w) of theoretical loading. The nanoparticles size was approximately of 350 nm with 66% of encapsulation efficiency. The everted gut sac model shows to be efficient to evaluate the drug permeation through the intestinal membrane. The results show that free praziquantel presents 4-fold times more permeation than praziquantel-loaded PLGA nanoparticles and physical mixture. For this drug, in special, this result can be interesting, since the nanoparticulate system can behave as a drug reservoir and/or to have a more localized effect in intestinal membrane for a prolonged period of time, since great amounts of parasites can be usually found in the mesenteric veins.     

Poly(lactide-co-glycolide) nanoparticles as carriers for norcantharidin

Norcantharidin (NCTD) is one of the new chemotherapy agents that have anti-tumor activity. However, the clinical potential of NCTD is limited by its high systemic toxicity, poor solubility in physiological environment and short half-life. In this paper, NCTD loaded poly(lactide-co-glycolide) (PLGA) nanoparticles for controlled delivery were prepared by using an interfacial deposition method. The resulting particles were characterized for their size, morphology, drug loading capacity, entrapment efficiency and in vitro drug release over an extended period of 12 days. The interfacial deposition technique succeeded in building a spherical, monodisperse nanoparticulate delivery system with high entrapment efficiency. The in vitro release lasts for more than 10 days showed a biphasic profile with an initial burst. The in vitro anti-tumor activity of NCTD-PLGA nanocapsules was assessed using the Human Hepatocellular Carcinoma cells SMMC-7721 by the MTT test. Ascites hepatoma (H-22H) and pulmonary adenocarcinoma (LA795) mice models were used to study the in vivo tumoricidal efficacy of NCTD delivery from the PLGA nanoparticles. The results demonstrate that i.v. or i.p. administration of this controlled release system could be of high clinical significance in cancer chemotherapy.     

Development and In Vitro Evaluation of Surface Modified Poly(lactide-co-glycolide) Nanoparticles with Chitosan-4-Thiobutylamidine

ABSTRACT

The objective of this study was to develop a nanoparticulate drug delivery system based on the surface modification of poly(lactide-co-glycolide) (PLGA) nanoparticles with a thiolated chitosan. PLGA nanoparticles were prepared by the emulsification-solvent evaporation method. Immobilization of chitosan to the surface of PLGA nanoparticles via amide bonds was mediated by a carbodiimide. Thiol groups were covalently bound to the chitosan surface of particles by reaction with 2-iminothiolane. Obtained nanoparticles were characterized in vitro regarding size, zeta potential, thiol group content, stability at different pH values, mucoadhesion, and drug release. Results demonstrated that the surface modification of PLGA nanoparticles with thiolated chitosan (chitosan-TBA) leads to nanoparticles of a mean diameter of 889.5 ± 72 nm and positive zeta potential of + 24.74 mV. The modified nanoparticles contained 7.32 ± 0.24 μmol thiol groups per gram nanoparticles. The size of nanoparticles was strongly influenced by the pH of the surrounding medium, being 925.0 ± 76.3 nm at pH 2 and 577.8 ± 66.7 nm at pH 7.4. Thiolated nanoparticles showed a 3.3-fold prolonged residence time on the mucosa and an unchanged release profile in comparison to unmodified PLGA nanoparticles. These data suggest that surface modified chitosan-TBA conjugate PLGA nanoparticles have the potential to be used as mucoadhesive drug delivery system.