Search Results (6)

The efficient oral delivery of therapeutic proteins and peptides poses a tremendous challenge due to their inherent instability, large molecular size, and susceptibility to enzymatic degradation. Several nanocarrier systems, such as liposomes, solid lipid nanoparticles, and polymeric nanoparticles, have been explored to overcome these problems. Liposomes and other lipid-based nanocarriers show excellent biocompatibility and the ability to encapsulate hydrophobic and hydrophilic drugs; however, they often suffer from poor structural stability, premature leakage of the loaded drugs, and poor encapsulation efficiency for macromolecular peptides and proteins. On the other hand, polymeric nanoparticles are more stable and allow better control over drug release; nevertheless, they usually lack the necessary biocompatibility and cellular uptake efficiency. Recently, lipid-polymer hybrid nanoparticles (LPHNs) have emerged as an advanced solution combining the structural stability of polymers and the biocompatibility and surface functionalities of lipids to enhance the controlled release, stability, and bioavailability of protein and peptide drugs. In this review, an attempt was made to set a clear definition of the LPHNs and extend the concept and area, so to our knowledge, this is the first review that highlights six categories of the LPHNs based on their anatomy. Moreover, this review offers a detailed analysis of LPHN preparation methods, including conventional and nonconventional one-step and two-step processes, nanoprecipitation, microfluidic mixing, and emulsification methods. Moreover, the material attributes and critical process parameters affecting the output of the preparation methods were illustrated with supporting examples to enable researchers to select the suitable preparation method, excipients, and parameters to be manipulated to get the LPHNs with the predetermined quality. The number of reviews focusing on the formulation of peptide/protein pharmaceutics usually focus on a specific drug like insulin. To our knowledge, this is the first review that generally discusses LPHN-based delivery of biopharmaceuticals. by discussing representative examples of previous reports comparing them to a variety of nanocarrier systems to show the potentiality of the LPHNs to deliver peptides and proteins. Moreover, some ideas and suggestions were proposed by the authors to tackle some of the shortcomings highlighted in these studies. By presenting this comprehensive overview of LPHN preparation strategies and critically analyzing literature studies on this topic and pointing out their strong and weak points, this review has shown the gaps and enlightened avenues for future research. Full article

In this study, we present a new type of polymer-free hydrogel made only from nonionic surfactants, oil, and water. Such a system is produced by taking advantage of the physicochemical behavior and interactions between nonionic surfactants and oil and water phases, according to a process close to spontaneous emulsification used in the production of nano-emulsions. Contrary to the classical process of emulsion-based gel formulation, we propose a simple one-step approach. Beyond the originality of the concept, these nanoemulgels appear as very promising systems able to encapsulate and deliver various molecules with different solubilities. In the first section, we propose a comprehensive investigation of the gel formation process and its limits through oscillatory rheological characterization, characterization of the sol/gel transitions, and gel strength. The second section is focused on the follow-up of the release of an encapsulated model hydrophilic molecule and on the impact of the rheological gel properties on the release profiles. Full article

Cell microencapsulation in gel beads contributes to many biomedical processes and pharmaceutical applications. Small beads (<300 µm) offer distinct advantages, mainly due to improved mass transfer and mechanical strength. Here, we describe, for the first time, the encapsulation of human-bone-marrow-derived mesenchymal stem cells (hBM-MSCs) in small-sized microspheres, using one-step emulsification by internal gelation. Small (127–257 µm) high-mannuronic-alginate microspheres were prepared at high agitation rates (800–1000 rpm), enabling control over the bead size and shape. The average viability of encapsulated hBM-MSCs after 2 weeks was 81 ± 4.3% for the higher agitation rates. hBM-MSC-loaded microspheres seeded within a glycosaminoglycan (GAG) analogue, which was previously proposed as a mechanically equivalent implant for degenerate discs, kept their viability, sphericity, and integrity for at least 6 weeks. A preliminary in vivo study of hBM-MSC-loaded microspheres implanted (via a GAG-analogue hydrogel) in a rat injured intervertebral disc model demonstrated long-lasting viability and biocompatibility for at least 8 weeks post-implantation. The proposed method offers an effective and reproducible way to maintain long-lasting viability in vitro and in vivo. This approach not only utilizes the benefits of a simple, mild, and scalable method, but also allows for the easy control of the bead size and shape by the agitation rate, which, overall, makes it a very attractive platform for regenerative-medicine applications. Full article

Hydrogel conjugates based on chitosan and an essential oil were synthetized by an ultrasound-assisted emulsification approach. Rheology studies revealed a gel-type structure with pronounced compactness and flexibility while SEM showed the formation of a two-level ordered network with highly interconnected pores. The swelling studies indicated a pH-dependent behavior with a significant overshooting effect. The synergistic effects of the components in clove essential oil led to a strong antioxidant character and an enhanced antimicrobial activity of the conjugate hydrogels. The bioactivity was maintained for 6 months, despite a slight decrease in the antimicrobial effect. Hydrogel conjugates were found to be very stable even after two months immersed in acidic solutions that would otherwise dissolve the chitosan matrix. Ultrasound emulsification was proved as an efficient one-step loading method of hydrophobic clove essential oil into hydrophilic chitosan matrix. It was found that clove oil and its components have a double role. Besides providing bioactivity, they also behave as gelation-inducing agents, acting as an alternative to the classical chemical cross-linkers to ensure the good physical and chemical stabilization of chitosan. Full article

Recent years have witnessed significant progress in nanotechnology and pesticide research in pest control and crop protection. There are more motivations to develop nanoformulations that are less harmful to environment than conventional formulations. The use of nanosuspension has been proposed as a novel formulation to process poorly soluble pesticides. In this study, the lambda-cyhalothrin nanosuspension (LCNS) was prepared in a melt emulsification method. The prepared nanosuspension had a mean particle size of 12.0 ± 0.1 nm and a polydispersity index of 0.279 ± 0.135. The smaller particle size and polydispersity confer better wettability, stability and bioavailability than conventional suspension concentrates. The excellent properties of the nanosuspension were attributed to the reduced particle size and the emulsification and dispersion of the surfactants. The LCNS eliminates the need for organic solvents and significantly reduces the amount of surfactant required. The simple production process of LCNS saves production and equipment costs. The results indicate that lambda-cyhalothrin nanosuspensions would have a broad application prospect in agricultural production systems. Full article

A novel strategy was developed to synthesize uniform semi-interpenetrating polymer network (semi-IPN) microspheres by premix membrane emulsification combined with one-step polymerization. Synthesized poly(acrylic acid) (PAAc) polymer chains were added prior to the inner water phase, which contained N-isopropylacrylamide (NIPAM) monomer, N,N′-methylene bisacrylamide (MBA) cross-linker, and ammonium persulfate (APS) initiator. The mixtures were pressed through a microporous membrane to form a uniform water-in-oil emulsion. By crosslinking the NIPAM in a PAAc-containing solution, microspheres with temperature- and pH-responsive properties were fabricated. The semi-IPN structure and morphology of the microspheres were confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The average diameter of the obtained microspheres was approximately 6.5 μm, with Span values of less than 1. Stimuli-responsive behaviors of the microspheres were studied by the cloud-point method. The results demonstrated that semi-IPN microspheres could respond independently to both pH and temperature changes. After storing in a PBS solution (pH 7.0) at 4 °C for 6 months, the semi-IPN microspheres remained stable without a change in morphology or particle size. This study demonstrated a promising method for controlling the synthesis of semi-IPN structure microspheres with a uniform size and multiple functionalities. Full article