Pereskia aculeata leaves: properties and potentialities for the development of new products.

Pereskia aculeata Mill., known as Ora-Pro-Nobis or Barbados gooseberry, arouse the interest of food and pharmaceutical industries due to its bioactive compounds and mucilage. We conducted a peer-reviewed survey using Web of Science, Scopus, Scielo, Science Direct, and Scifinder platforms, as well as patent bases for new products. We selected articles which highlighted composition of leaves and applications in the development of new products. Mucilage shows great potential in the development of complexes or microparticles to transport active molecules. Reports on anti-inflammatory and anticancer properties of P. aculeata leaves open a research field to obtain pharmaceutical products. Emulsifying properties of mucilage have been explored in food processing. Another potential use is the development of films for functional and/or edible packaging. The polysaccharide chain, the main mucilage constituent, can interact with other biopolymers to be explored in colloidal chemistry for the production of biomaterials in the next years.

Distilled pyroligneous liquor obtained from Eucalyptus grandis and chitosan: physicochemical properties of the solution and films.

The pyroligneous liquor is a product obtained during the production of charcoal, with well-known antimicrobial activity. In this work, we characterized the physical chemistry properties of a formulation composed of distilled pyroligneous liquor (DPL), obtained from Eucalyptus grandis, and chitosan. A good interaction between the polymer and the solvent was observed. Auto-supported films were prepared with these systems and characterized with respect to their structure and photo-protection properties, water vapor permeability, and resistance to water and to thermal degradation. They present a semi-crystalline structure and are hygroscopic, but are stable under immersion for up to 7 days. The swelling degree in water is 300% in weight and the permeability to water vapor was between 30 and 45 g m-1 h-1 (for films with 80 to 10 µm, respectively). The obtained films are able to efficiently block the incident UVB and UVC radiation; the molar absorptivity decreases exponentially with increasing wavelength and is stable up to 300 °C. These properties confer desirable properties to the films, obtained from these precursors of a renewable source, to be used as coatings.

Targeted Drug Delivery and Treatment of Endoparasites with Biocompatible Particles of pH-Responsive Structure.

Biomaterials conceived for vectorization of bioactives are currently considered for biomedical, biological, and environmental applications. We have produced a pH-sensitive biomaterial composed of natural source alginate and chitosan polysaccharides for application as a drug delivery system via oral administration. The composite particle preparation was in situ monitored by means of isothermal titration calorimetry. The strong interaction established between the macromolecules during particle assembly led to 0.60 alginate/chitosan effective binding sites with an intense exothermic effect and negative enthalpy variation on the order of a thousand kcal/mol. In the presence of model drugs mebendazole and ivermectin, with relatively small and large structures, respectively, mebendazole reduced the amount of chitosan monomers available to interact with alginate by 27%, which was not observed for ivermectin. Nevertheless, a state of intense negative Gibbs energy and large entropic decrease was achieved, providing evidence that formation of particles is thermodynamically driven and favored. Small-angle X-ray scattering provided further evidence of similar surface aspects independent of the presence of drug. The physical responses of the particles to pH variation comprise partial hydration, swelling, and the predominance of positive surface charge in strong acid medium, whereas ionization followed by deprotonation leads to compaction and charge reversal rather than new swelling in mild and slightly acidic mediums, respectively. In vivo performance was evaluated in the treatment of endoparasites in Corydoras fish. Systematically with a daily base oral administration, particles significantly reduced the infections over 15 days of treatment. The experiments provide evidence that utilizing particles granted and boosted the action of the antiparasitic drugs, leading to substantial reduction or elimination of infection. Hence, the pH-responsive particles represent a biomaterial with prominent characteristics that is promising for the development of targeted oral drug delivery.