Influence of different stabilizers on the encapsulation of desmopressin acetate into PLGA nanoparticles

Tween® Preserves Enzyme Activity and Stability in PLGA Nanoparticles

Enzymes, as natural and potentially long-term treatment options, have become one of the most sought-after pharmaceutical molecules to be delivered with nanoparticles (NPs); however, their instability during formulation often leads to underwhelming results. Various molecules, including the Tween^® polysorbate series, have demonstrated enzyme activity protection but are often used uncontrolled without optimization. Here, poly(lactic-co-glycolic) acid (PLGA) NPs loaded with β-glucosidase (β-Glu) solutions containing Tween^® 20, 60, or 80 were compared. Mixing the enzyme with Tween^® pre-formulation had no effect on particle size or physical characteristics, but increased the amount of enzyme loaded. More importantly, NPs made with Tween^® 20:enzyme solutions maintained significantly higher enzyme activity. Therefore, Tween^® 20:enzyme solutions ranging from 60:1 to 2419:1 mol:mol were further analyzed. Isothermal titration calorimetry analysis demonstrated low affinity and unquantifiable binding between Tween^® 20 and β-Glu. Incorporating these solutions in NPs showed no effect on size, zeta potential, or morphology. The amount of enzyme and Tween^® 20 in the NPs was constant for all samples, but a trend towards higher activity with higher molar rapports of Tween^® 20:β-Glu was observed. Finally, a burst release from NPs in the first hour with Tween^®:β-Glu solutions was the same as free enzyme, but the enzyme remained active longer in solution. These results highlight the importance of stabilizers during NP formulation and how optimizing their use to stabilize an enzyme can help researchers design more efficient and effective enzyme loaded NPs.

Ciprofloxacin-loaded polymeric nanoparticles incorporated electrospun fibers for drug delivery in tissue engineering applications

Presented work focuses on the development of biodegradable polymer nanoparticles loaded with antibiotics as drug delivery systems deposited on electrospun scaffolds for tissue engineering. The innovative ciprofloxacin-loaded poly(DL-lactide-co-glycolide) NPs ensure a continuous slow release and high local concentration at the site of action for an optimal therapy. The local delivery of antibiotics as an integrated part of electrospun scaffolds offers an effective, safe, and smart enhancement supporting tissue regeneration. Presented data provides solid scientific evidence for fulfilling the requirements of local nano antibiotic delivery systems with biodegradability and biocompatibility for a wide range of tissue engineering applications, including middle ear tissues (e.g., tympanic membranes) which are subject to bacterial infections. Further characterization of such systems, including in vivo studies, is required to ensure successful transfer from lab to clinical applications. Graphical abstract .

A comparison of acyl-moieties for noncovalent functionalization of PLGA and PEG-PLGA nanoparticles with a cell-penetrating peptide

Noncovalent functionalization with acylated cell-penetrating peptides achieves an efficient cellular uptake of PLGA and PEG-PLGA nanoparticles.

Development of a fast and precise method for simultaneous quantification of the PLGA monomers lactic and glycolic acid by HPLC

Poly(lactide-co-glycolide acid) (PLGA) is an extraordinary well-described polymer and has excellent pharmaceutical properties like high biocompatibility and good biodegradability. Hence, it is one of the most used materials for drug delivery and biomedical systems, also being present in several US Food and Drug Administration-approved carrier systems and therapeutic devices. For both applications, the quantification of the polymer is inalienable. During the development of a production process, parameters like yield or loading efficacy are essential to be determined. Although PLGA is a well-defined biomaterial, it still lacks a sensitive and convenient quantification approach for PLGA-based systems. Thus, we present a novel method for the fast and precise quantification of PLGA by RP-HPLC. The polymer is hydrolyzed into its monomers, glycolic acid and lactic acid. Afterwards, the monomers are derivatized with the absorption-enhancing molecule 2,4′-dibromoacetophenone. Furthermore, the wavelength of the derivatized monomers is shifted to higher wavelengths, where the used solvents show a lower absorption, increasing the sensitivity and detectability. The developed method has a detection limit of 0.1 µg/mL, enabling the quantification of low amounts of PLGA. By quantifying both monomers separately, information about the PLGA monomer ratio can be also directly obtained, being relevant for degradation behavior. Compared to existing approaches, like gravimetric or nuclear magnetic resonance measurements, which are tedious or expensive, the developed method is fast, ideal for routine screening, and it is selective since no stabilizer or excipient is interfering. Due to the high sensitivity and rapidity of the method, it is suitable for both laboratory and industrial uses.

In vitro and in vivo evaluation of desmopressin-loaded poly(D,L-lactic-co-glycolic acid) nanoparticles for its potential use in cancer treatment

AIM

To develop and characterize the antitumor activity of poly(D,L-lactic-co-glycolic acid) nanoparticles loaded with hemostatic and anticancer drug desmopressin (dDAVP).

MATERIALS & METHODS

After full physicochemical characterization, anticancer activity of dDAVP-loaded poly(D,L-lactic-co-glycolic acid) nanoparticles (NPdDAVP) was evaluated in vitro and in vivo on a highly aggressive breast cancer model.

RESULTS

After efficiently loading desmopressin in poly(D,L-lactic-co-glycolic acid) matrix, NPdDAVP exhibited suitable physicochemical characteristics for biomedical applications. NPdDAVP displayed a potent cytostatic effect in vitro, inhibiting tumor cell proliferation and colony forming ability. Moreover, intravenous treatment using nanoparticulated-dDAVP inhibited tumor progression and prolonged survival in animals bearing rapidly-growing mammary tumors.

CONCLUSION

Within the framework of promising dDAVP repurposing studies, these findings support further preclinical development of the NPdDAVP for the management of highly aggressive cancer.