Polyelectrolyte coated multilayered liposomes (nanocapsules) for the treatment of Helicobacter pylori infection

Nanomedicine for the eradication of Helicobacter pylori: recent advances, challenges and future perspective

Helicobacter pylori infection is linked to gastritis, ulcers and gastric cancer. Nanomedicine offers a promising solution by utilizing nanoparticles for precise drug delivery, countering antibiotic resistance and delivery issues. Nanocarriers such as liposomes and nanoparticles enhance drug stability and circulation, targeting infection sites through gastric mucosa characteristics. Challenges include biocompatibility, stability, scalability and personalized therapies. Despite obstacles, nanomedicine's potential for reshaping H. pylori eradication is significant and showcased in this review focusing on benefits, limitations and future prospects of nanomedicine-based strategies.

Microparticles and nanoparticles-based approaches to improve oral treatment of Helicobacter pylori infection

Helicobacter pylori is a gram-negative, spiral-shaped, flagellated bacterium that colonizes the stomach of half the world's population. Helicobacter pylori infection causes pathologies of varying severity. Standard oral therapy fails in 15-20% since the barriers of the oral route decrease the bioavailability of antibiotics and the intrinsic factors of bacteria increase the rates of resistance. Nanoparticles and microparticles are promising strategies for drug delivery into the gastric mucosa and targeting H. pylori. The variety of building blocks creates systems with distinct colloidal, surface, and biological properties. These features improve drug-pathogen interactions, eliminate drug depletion and overuse, and enable the association of multiple actives combating H. pylori on several fronts. Nanoparticles and microparticles are successfully used to overcome the barriers of the oral route, physicochemical inconveniences, and lack of selectivity of current therapy. They have proven efficient in employing promising anti-H. pylori compounds whose limitation is oral route instability, such as some antibiotics and natural products. However, the current challenge is the applicability of these strategies in clinical practice. For this reason, strategies employing a rational design are necessary, including in the development of nano- and microsystems for the oral route.

Biomaterials for Helicobacter pylori therapy: therapeutic potential and future perspectives

Helicobacter pylori (H. pylori) is the main cause of gastric adenocarcinoma. However, the traditional antibiotic treatment of H. pylori is limited due to increased antibiotic resistance and low efficacy; low drug delivery efficiency and difficulties in eradicating H. pylori that is present intracellularly or in biofilms cause further setbacks. Biomaterials that can protect drugs against stomach acid, target lesions, control drug release, destroy biofilms, and exhibit unique antibacterial mechanisms and excellent biocompatibility have emerged as attractive tools for H. pylori eradication, particularly for drug-resistant strains. Herein, we review the virulence mechanisms, current drug treatments, and antibiotic resistance of H. pylori strains. Furthermore, recent advances in the development of biomaterials, including nanoparticles (such as lipid-based nanoparticles, polymeric nanoparticles, and inorganic nanoparticles), microspheres, and hydrogels, for effective and precise therapy of H. pylori and different types of therapeutic mechanisms, as well as future perspectives, have also been summarized.

Cosmetic-Derived Mannosylerythritol Lipid-B-Phospholipid Nanoliposome: An Acid-Stabilized Carrier for Efficient Gastromucosal Delivery of Amoxicillin for In Vivo Treatment of Helicobacter pylori

Helicobacter pylori infection is a leading cause of gastritis and peptic ulcer. Current treatments for H. pylori are limited by the increase in antibiotic-resistant strains and low drug delivery to the infection site, indicating the need for effective delivery systems of antibiotics. Although liposomes are the most successful drug delivery carriers that have already been applied commercially, their acidic stability still stands as a problem. Herein, we developed a novel nanoliposome using cosmetic raw materials of mannosylerythritol lipid-B (MEL-B), soy bean lecithin, and cholesterol, namely, LipoSC-MELB. LipoSC-MELB exhibited enhanced stability under the simulated gastric-acid condition, owing to its strong intermolecular hydrogen-bond interactions caused by the incorporation of MEL-B. Moreover, amoxicillin-loaded LipoSC-MELB (LipoSC-MELB/AMX) had a particle size of approximately 100 nm and exhibited sustained drug release under varying pH conditions (pH 3-7). Besides, LipoSC-MELB/AMX exhibited significantly higher anti-H. pylori and anti-H. pylori biofilm activity as compared with free AMX. Furthermore, LipoSC-MELB was able to carry AMX across the barriers of gastric mucus and H. pylori biofilms. Remarkably, in vivo assays indicated that LipoSC-MELB/AMX was effective in treating H. pylori infection and its associated gastritis and gastric ulcers. Overall, the findings of this study showed that LipoSC-MELB was effective for gastromucosal delivery of amoxicillin to improve its bioavailability for the treatment of H. pylori infection.

Polymer-Modified Liposomes for Drug Delivery: From Fundamentals to Applications

Liposomes are highly advantageous platforms for drug delivery. To improve the colloidal stability and avoid rapid uptake by the mononuclear phagocytic system of conventional liposomes while controlling the release of encapsulated agents, modification of liposomes with well-designed polymers to modulate the physiological, particularly the interfacial properties of the drug carriers, has been intensively investigated. Briefly, polymers are incorporated into liposomes mainly using “grafting” or “coating”, defined according to the configuration of polymers at the surface. Polymer-modified liposomes preserve the advantages of liposomes as drug-delivery carriers and possess specific functionality from the polymers, such as long circulation, precise targeting, and stimulus-responsiveness, thereby resulting in improved pharmacokinetics, biodistribution, toxicity, and therapeutic efficacy. In this review, we summarize the progress in polymer-modified liposomes for drug delivery, focusing on the change in physiological properties of liposomes and factors influencing the overall therapeutic efficacy.

Bacteria-targeting chitosan/carbon dots nanocomposite with membrane disruptive properties improve eradication rate of Helicobacter pylori

We designed a bacteria-targeting and membrane disrupting nanocomposite for successful antibiotic treatment of Helicobacter pylori (H. pylori) infections in the present study. The antibacterial nanocomposite was prepared from thiolated-ureido-chitosan (Cys-U-CS) and anionic poly (malic acid) (PMLA) via electrostatic interaction decorated with dual functional ammonium citrate carbon quantum dots (CDs). Cys-U-CS serves as a targeting building block for attaching antibacterial nanocomposite onto bacterial cell surface through Urel-mediated protein channel. Simultaneously, membrane disrupting CDs generate ROS and lyse the bacterial outer membrane, allowing antibiotics to enter the intracellular cytoplasm. As a result, Cys-U-CS/PMLA@CDs nanocomposite (UCPM-NPs) loaded with the antibiotic amoxicillin (AMX) not only effectively target and kill bacteria in vitro via Urel-mediated adhesion but also efficiently retain in the stomach where H. pylori reside, serving as an effective drug carrier for abrupt on-site release of AMX into the bacterial cytoplasm. Furthermore, since thiolated-chitosan has a mucoadhesive property, UCPM-NPs may adhere to the stomach mucus layer and pass through it swiftly. According to our results, bacterial targeting is crucial for guaranteeing successful antibiotic treatment. The bacteria targeting UCPM-NPs with membrane disruptive ability may establish a promising drug delivery system for the effective targeted delivery of antibiotics to treat H. pylori infections.

Surface modification of nano-drug delivery systems for enhancing antibiotic delivery and activity

Rampant antimicrobial resistance calls for innovative strategies to effectively control bacterial infections, enhance antibacterial efficacy, minimize side effects, and protect existing antibiotics in the market. Therefore, to enhance the delivery of antibiotics and increase their bioavailability and accumulation at the site of infection, the surfaces of nano-drug delivery systems have been diversely modified. This strategy applies various covalent and non-covalent techniques to introduce specific coating materials that have been found to be effective against various sensitive and resistant microorganisms. In this review, we discuss the techniques of surface modification of nanocarriers loaded with antibacterial agents. Furthermore, saccharides, polymers, peptides, antibiotics, enzymes and cell membranes coatings that have been used for surface functionalization of nano-drug delivery systems are described, emphasizing current approaches for enhancing delivery, bioavailability, and efficacy of surface-modified antibacterial nanocarriers at infection sites. This article offers a critical overview of the potential of surface-modified antibacterial nanocarriers to overcome the limitations of conventional antibiotics in the treatment of bacterial infections. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Development and characterization of layer-by-layer coated liposomes with poly(L-lysine) and poly(L-glutamic acid) to increase their resistance in biological media

Multilayered coated liposomes were prepared using the layer-by-layer (LbL) technique in an effort to improve their stability in biological media. The formulation strategy was based on the alternate deposition of two biocompatible and biodegradable polyelectrolytes - poly(L-lysine) (PLL) and poly(L-glutamic acid) (PGA) - on negatively charged small unilamellar vesicles (SUVs). Some parameters of the formulation process were optimized such as the polyelectrolyte concentration and the purification procedure. This optimized procedure has allowed the development of very homogeneous formulations of liposomes coated with up to 6 layers of polymers (so-called layersomes). The coating was characterized by dynamic light scattering (DLS), zeta potential measurements and Förster resonance energy transfer (FRET) between two fluorescently labeled polyelectrolytes. Studies on the stability of the formulations at 4 °C in a buffered solution have shown that most structures are stable over 1 month without impacting their encapsulation capacity. In addition, fluorophore release experiments have demonstrated a better resistance of the layersomes in the presence of a non-ionic detergent (Triton™ X-100) as well as in the presence of phospholipase A₂ and human plasma. In conclusion, new multilayered liposomes have been developed to increase the stability of conventional liposomes in biological environments.

Advances in Oral Drug Delivery for Regional Targeting in the Gastrointestinal Tract - Influence of Physiological, Pathophysiological and Pharmaceutical Factors

The oral route is by far the most common route of drug administration in the gastrointestinal tract and can be used for both systemic drug delivery and for treating local gastrointestinal diseases. It is the most preferred route by patients, due to its advantages, such as ease of use, non-invasiveness, and convenience for self-administration. Formulations can also be designed to enhance drug delivery to specific regions in the upper or lower gastrointestinal tract. Despite the clear advantages offered by the oral route, drug delivery can be challenging as the human gastrointestinal tract is complex and displays a number of physiological barriers that affect drug delivery. Among these challenges are poor drug stability, poor drug solubility, and low drug permeability across the mucosal barriers. Attempts to overcome these issues have focused on improved understanding of the physiology of the gastrointestinal tract in both healthy and diseased states. Innovative pharmaceutical approaches have also been explored to improve regional drug targeting in the gastrointestinal tract, including nanoparticulate formulations. This review will discuss the physiological, pathophysiological, and pharmaceutical considerations influencing drug delivery for the oral route of administration, as well as the conventional and novel drug delivery approaches. The translational challenges and development aspects of novel formulations will also be addressed.

Eradication of Helicobacter pylori: the power of nanosized formulations

Helicobacter pylori is a pathogen that is considered to cause several gastric disorders such as chronic gastritis, peptic ulcer and even gastric carcinoma. The current therapeutic regimens mainly constitute of a combination of several antimicrobial agents and proton pump inhibitors. However, the prevalence of antibiotic resistance has been significantly lowering the cure rates over the years. Nanocarriers possess unique strengths in this regard owing to the fact that they can protect the drugs (such as antibiotics) from the harsh environment in the stomach, penetrate the mucosal barrier and deliver drugs to the desired site. In this review we summarized recent studies of different antibacterial agents orally delivered by nanosized carriers for the eradication of H. pylori.

Modification of drug delivery to improve antibiotic targeting to the stomach

The obstacles to the successful eradication of Helicobacter pylori infections include the presence of antibiotic-resistant bacteria and therapy requiring multiple drugs with complicated dosing schedules. Other obstacles include bacterial residence in an environment where high antibiotic concentrations are difficult to achieve. Biofilm production by the bacteria is an additional challenge to the effective treatment of this infection. Conventional oral formulations used in the treatment of this infection have a short gastric residence time, thus limiting the duration of exposure of drug to the bacteria. This review summarizes the current research in the development of gastroretentive formulations and the prospective future applications of this approach in the targeted delivery of drugs such as antibiotics to the stomach.

Recent advances in liposome surface modification for oral drug delivery

Oral delivery via the gastrointestinal (GI) tract is the dominant route for drug administration. Orally delivered liposomal carriers can enhance drug solubility and protect the encapsulated theraputic agents from the extreme conditions found in the GI tract. Liposomes, with their fluid lipid bilayer membrane and their nanoscale size, can significantly improve oral absorption. Unfortunately, the clinical applications of conventional liposomes have been hindered due to their poor stability and availability under the harsh conditions typically presented in the GI tract. To overcome this problem, the surface modification of liposomes has been investigated. Although liposome surface modification has been extensively studied for oral drug delivery, no review exists so far that adequately covers this topic. The purpose of this paper is to summarize and critically analyze emerging trends in liposome surface modification for oral drug delivery.

Modification of Spherical Polyelectrolyte Brushes by Layer-by-Layer Self-Assembly as Observed by Small Angle X-ray Scattering

Multilayer modified spherical polyelectrolyte brushes were prepared through alternate deposition of positively charged poly(allylamine hydrochloride) (PAH) and negatively charged poly-l-aspartic acid (PAsp) onto negatively charged spherical poly(acrylic acid) (PAA) brushes (SPBs) on a poly(styrene) core. The charge reversal determined by the zeta potential indicated the success of layer-by-layer (LBL) deposition. The change of the structure during the construction of multilayer modified SPBs was observed by small-angle X-ray scattering (SAXS). SAXS results indicated that some PAH chains were able to penetrate into the PAA brush for the PAA-PAH double-layer modified SPBs whereas part of the PAH moved towards the outer layer when the PAsp layer was loaded to form a PAA-PAH-PAsp triple-layer system. The multilayer modified SPBs were stable upon changing the pH (5 to 9) and ionic strength (1 to 100 mM). The triple-layer modified SPBs were more tolerated to high pH (even at 11) compared to the double-layer ones. SAXS is proved to be a powerful tool for studying the inner structure of multilayer modified SPBs, which can establish guidelines for the a range of potential applications of multilayer modified SPBs.

Nanoparticle approaches against bacterial infections

Despite the wide success of antibiotics, the treatment of bacterial infections still faces significant challenges, particularly the emergence of antibiotic resistance. As a result, nanoparticle drug delivery platforms including liposomes, polymeric nanoparticles, dendrimers, and various inorganic nanoparticles have been increasingly exploited to enhance the therapeutic effectiveness of existing antibiotics. This review focuses on areas where nanoparticle approaches hold significant potential to advance the treatment of bacterial infections. These areas include targeted antibiotic delivery, environmentally responsive antibiotic delivery, combinatorial antibiotic delivery, nanoparticle-enabled antibacterial vaccination, and nanoparticle-based bacterial detection. In each area we highlight the innovative antimicrobial nanoparticle platforms and review their progress made against bacterial infections.

Gastroretentive drug delivery systems for the treatment of Helicobacter pylori

Helicobacter pylori (H. pylori) is one of the most common pathogenic bacterial infections and is found in the stomachs of approximately half of the world's population. It is the primary known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. However, combined drug therapy as the general treatment in the clinic, the rise of antibiotic-resistant bacteria, adverse reactions and poor patient compliance are major obstacles to the eradication of H. pylori. Oral site-specific drug delivery systems that could increase the longevity of the treatment agent at the target site might improve the therapeutic effect and avoid side effects. Gastroretentive drug delivery systems potentially prolong the gastric retention time and controlled/sustained release of a drug, thereby increasing the concentration of the drug at the application site, potentially improving its bioavailability and reducing the necessary dosage. Recommended gastroretentive drug delivery systems for enhancing local drug delivery include floating systems, bioadhesive systems and expandable systems. In this review, we summarize the important physiological parameters of the gastrointestinal tract that affect the gastric residence time. We then focus on various aspects useful in the development of gastroretentive drug delivery systems, including current trends and the progress of novel forms, especially with respect to their application for the treatment of H. pylori infections.

Eradication of Helicobacter pylori: Past, present and future

Helicobacter pylori is the major cause of chronic gastritis and peptic ulcers. Since the classification as a group 1 carcinogenic by International Agency for Research on Cancer, the importance of the complete H. pylori eradication has obtained a novel meaning. Hence, several studies have been made in order to deepen the knowledge in therapy strategies. However, the current therapy presents unsatisfactory eradication rates due to the lack of therapeutic compliance, antibiotic resistance, the degradation of antibiotics at gastric pH and their insufficient residence time in the stomach. Novel approaches have been made in order to overcome these limitations. The purpose of this review is to provide an overview about the current therapy and its limitations, while highlighting the possibility of using micro- and nanotechnology to develop gastric drug delivery systems, overcoming these difficulties in the future.

Release retardation of model protein on polyelectrolyte-coated PLGA nano- and microparticles

PEM capsules have been proposed for vehicles of drug microencapsulation, with the release triggered by pH, salt, magnetic field, or light. When built on another carrier encapsulating drugs, such as nanoparticles, it could provide additional release barrier to the releasing drug, providing further control to drug release. Although liposomes have received considerable attention with PEM coating for sustained drug release, similar results employing PEM built on poly(lactic-co-lycolic acid) (PLGA) particles is scant. In this work, we demonstrate that the build-up pH and polyelectrolyte pairs of PEM affect the release retardation of BSA from PLGA particles. PAH/PSS pair, the most commonly used polyelectrolyte pair, was used in comparison with PLL/DES. In addition, we also demonstrate that the release retardation effect of PEM-coated PLGA particles diminishes as the particle size increases. We attribute this to the diminishing relative thickness of the PEM coating with respect to the size of the particle as the particle size increases, reducing the diffusional resistance of the PEM.

Pharmaceutical suspension containing both immediate/sustained-release amoxicillin-loaded gelatin nanoparticles: preparation and in vitro characterization

Pharmaceutical suspension containing oral dosage forms delivering both immediate-release and sustained-release amoxicillin was developed as a new dosage form to eradicate Helicobacter pylori. Amoxicillin-loaded gelatin nanoparticles are able to bind with the mucosal membrane after delivery to the stomach and could escalate the effectiveness of a drug, providing dual release. The objective of this study was to develop amoxicillin nanoparticles using innovative new technology – the Büchi Nano Spray Dryer B-90 – and investigate such features as drug content, particle morphology, yield, in vitro release, flow properties, and stability. The nanoparticles had an average particle size of 571 nm. The drug content and percentage yield was 89.2% ± 0.5% and 93.3% ± 0.6%, respectively. Angle of repose of nanoparticle suspension was 26.3° and bulk density was 0.59 g/cm³. In vitro drug release of formulations was best fitted by first-order and Peppas models with R² of 0.9841 and 0.9837 respectively; release profile was 15.9%, while; for the original drug, amoxicillin, under the same conditions, 90% was released in the first 30 minutes. The nanoparticles used in this study enabled sustained release of amoxicillin over an extended period of time, up to 12 hours, and were stable for 12 months under accelerated storage conditions of 25°C ± 2°C and 60% ± 5% relative humidity.

Genipin-cross-linked fucose-chitosan/heparin nanoparticles for the eradication of Helicobacter pylori

Helicobacter pylori is a significant human pathogen that recognizes specific carbohydrate receptors, such as the fucose receptor, and produces the vacuolating cytotoxin, which induces inflammatory responses and modulates the cell-cell junction integrity of the gastric epithelium. The clinical applicability of topical antimicrobial agents was needed to complete the eradication of H. pylori in the infected fundal area. In the present study, we combined fucose-conjugated chitosan and genipin-cross-linking technologies in preparing multifunctional genipin-cross-linked fucose-chitosan/heparin nanoparticles to encapsulate amoxicillin of targeting and directly make contact with the region of microorganism on the gastric epithelium. The results show that the nanoparticles effectively reduced drug release at gastric acids and then released amoxicillin in an H. pylori survival situation to inhibit H. pylori growth and reduce disruption of the cell-cell junction protein in areas of H. pylori infection. Furthermore, with amoxicillin-loaded nanoparticles, a more complete H. pylori clearance effect was observed, and H. pylori-associated gastric inflammation in an infected animal model was effectively reduced.

Dual drug delivery system for targeting H. pylori in the stomach: preparation and in vitro characterization of amoxicillin-loaded Carbopol® nanospheres

Background and methods:

A dual (immediate/sustained-release) oral amoxicillin suspension was developed as a new dosage form to eradicate Helicobacter pylori. Carbopol^®-loaded amoxi-cillin nanospheres could bind with the mucosa after delivery to the stomach and could increase the efficiency of the drug, providing both an immediate and a sustained action.

Results:

The objective of this research was to develop amoxicillin nanospheres using a spray-drying technique and to investigate such features as their particle size, drug content, percentage yield, surface morphology, in vitro release, and stability. The nanospheres had a particle size range of 280–320 nm after optimizing the preparation method using a central composite design. The drug content and percentage yield was 85.3% ± 0.7% and 92.8% ± 0.9%, respectively. The in vitro release profile of the amoxicillin nanospheres was consistent with a Korsmeyer-Peppas pattern, and the release after one hour was 19%, while for the original drug, amoxicillin, under the same conditions, 90% was released in the first 30 minutes.

Conclusion:

The nanospheres used in this study enabled controlled release of amoxicillin over an extended period of time for up to 12 hours and the formulation was stable for 12 months.

Polyelectrolyte stabilized multilayered liposomes for oral delivery of paclitaxel

Paclitaxel (PTX) loaded layersome formulations were prepared using layer-by-layer assembly of the polyelectrolytes over liposomes. Stearyl amine was utilized to provide positive charge to the liposomes, which were subsequently coated with anionic polymer polyacrylic acid (PAA) followed by coating of cationic polymer polyallylamine hydrochloride (PAH). Optimization of various process variables were carried out and optimized formulation was found to have particle size of 226 ± 17.61 nm, PDI of 0.343 ± 0.070, zeta potential of +39.9 ± 3.79 mV and encapsulation efficiency of 71.91 ± 3.16%. The developed formulation was further subjected to lyophilization using a universal stepwise freeze drying cycle. The lyophilized formulation was found to be stable in simulated gastrointestinal fluids and at accelerated stability conditions. In vitro drug release studies revealed that layersome formulation was able to sustain the drug release for 24 h; release pattern being Higuchi kinetics. Furthermore, cell culture experiments showed higher uptake of layersomes from lung adenocarcinoma (A549) cell lines as compared to free drug. This was subsequently corroborated by MTT assay, which revealed IC50 value of 29.37 μg/ml for developed layersome formulation in contrast to 35.42 μg/ml for free drug. The in vivo pharmacokinetics studies revealed about 4.07 fold increase in the overall oral bioavailability of PTX as compared to that of free drug. In vivo antitumor efficacy in DMBA induced breast tumor model showed significant reduction in the tumor growth as compared to the control and comparable to that of i.v. Taxol(®). In addition, the toxicity studies were carried out to confirm the safety profile of the developed formulation and it was found to be significantly higher as compared to Taxol(®). Therefore, the developed formulation strategy can be fruitfully exploited to improve the oral deliverability of difficult-to deliver drugs.

Preparation of chondroitin sulfate nanocapsules for use as carries by the interfacial polymerization method

In this paper, the method of interfacial polymerization in emulsion was employed to fabricate chondroitin sulfate-methacrylate (ChSMA) nanocapsules, in which poor water-soluble drug of indomethacin (IND) could be effectively encapsulated. The morphology and the size distribution of synthesized nanocapsules were characterized by field emission scanning electron microscopy (FESEM) and dynamic light scattering (DLS) techniques. The quantitative drug loading was investigated. The IND/ChSMA noodle-like self-assemblies were observed with the increase of IND feed concentration, and the interactions between IND and ChSMA were illuminated by FT-IR and XRD measurements. The in vitro drug release of IND-loaded nanocapsules and IND/ChSMA self-assemblies were also carried out in simulated body fluid pH 7.4 at 37°C.

Development of novel nanoparticles shelled with heparin for berberine delivery to treat Helicobacter pylori

Various approaches have been proposed to overcome the unpleasant side-effects associated with antibiotic treatment for Helicobacter pylori. The limited effectiveness of such approaches has forced researchers to consider alternative strategies to eliminate H. pylori infection. The plant alkaloid berberine is known to significantly reduce proliferation of H. pylori. To localize berberine to the site of H. pylori infection, this study developed a novel nanoparticle berberine carrier with a heparin shell. Analysis of a simulated gastrointestinal medium indicated that the proposed in vitro drug carrier system effectively controlled the release of berberine, which interacted specifically with the intercellular space at the site of H. pylori infection. Furthermore, the prepared nanoparticles significantly increased the suppressive effect of berberine on H. pylori growth while efficiently reducing cytotoxic effects in H. pylori-infected cells.

Development of novel nanoparticles shelled with heparin for berberine delivery to treat Helicobacter pylori

Various approaches have been proposed to overcome the unpleasant side-effects associated with antibiotic treatment for Helicobacter pylori. The limited effectiveness of such approaches has forced researchers to consider alternative strategies to eliminate H. pylori infection. The plant alkaloid berberine is known to significantly reduce proliferation of H. pylori. To localize berberine to the site of H. pylori infection, this study developed a novel nanoparticle berberine carrier with a heparin shell. Analysis of a simulated gastrointestinal medium indicated that the proposed in vitro drug carrier system effectively controlled the release of berberine, which interacted specifically with the intercellular space at the site of H. pylori infection. Furthermore, the prepared nanoparticles significantly increased the suppressive effect of berberine on H. pylori growth while efficiently reducing cytotoxic effects in H. pylori-infected cells.

Retrospective on the future of polyelectrolyte multilayers

The layer-by-layer, or multilayer, method of thin film growth has evolved into a widely-used enabling technology. Starting in the mid 1990's, an exponentially increasing number of publications on the topic, many appearing in this Journal, have shown how multilayers may be adapted to passive and active coatings, devices and architectures. Looking forward, this Perspective briefly summarizes some of the most promising emerging ideas and applications.