Newly Synthesized Lignin Microparticles as Bioinspired Oral Drug-Delivery Vehicles: Flavonoid-Carrier Potential and In Vitro Radical-Scavenging Activity

Abstract

The aim of the present study was to synthesize lignin microparticles, to evaluate their physicochemical, spectral, morphological and structural characteristics, to examine their encapsulation and in vitro release potential and behaviour towards the flavonoid morin in simulated physiological medium and to assess the in vitro radical-scavenging potential of the morin-loaded lignin microcarrier systems. The physicochemical, structural and morphological characteristics of alkali lignin, lignin particles (LP) and morin-encapsulated lignin microparticles (LMP) were determined based on particle size distribution, SEM, UV/Vis spectrophotometric, FTIR and potentiometric titration analyses. The encapsulation efficiency of LMP was 98.1%. The FTIR analyses proved that morin was successfully encapsulated in the LP without unexpected chemical reactions between the flavonoid and the heteropolymer. The in vitro release performance of the microcarrier system was successfully mathematically described by Korsmeyer–Peppas and the sigmoidal models outlining the general role of diffusion during the initial stages of the in vitro release process in simulated gastric fluid (SGF), and the predominant contribution of biopolymer relaxation and erosion was determined in simulated intestinal medium (SIF). The higher radical-scavenging potential of LMP, as compared to that of LP, was proven via DPPH and ABTS assays. The synthesis of lignin microcarriers not only provides a facile approach for the utilization of the heteropolymer but also determines its potential for the design of drug-delivery matrices.

Menadione Contribution to the In Vitro Radical Scavenging Potential of Phytochemicals Naringenin and Lignin

“…Moreover, the higher DPPH radical scavenging activity of vitamin K 3 as compared to that of naringenin indicated that an increase in the number of phenolic hydroxyl groups did not necessarily lead to higher antioxidant potential values. Similar results were observed by Ivanova et al (2023) [32].…”

“…The absorbance was measured at λ = 517 nm. DPPH-scavenging activity (DPPH, %) was calculated according to [32].…”

“…The method comprised of the addition of 200 µL sample to 3.6 mL of ABTS solution and spectrophotometric measurement of the absorbance at the same wavelength. The radical scavenging activity is reported as ABTS radical inhibition (%) [56], calculated according to [32].…”

“…The natural heteropolymer lignin and its derivatives are acknowledged as alternative candidates for the design of novel medicinal products and drug-delivery formulations due to their valuable biological activities, such as antioxidant, anti-inflammatory, antidiabetic, antiviral, and antitumor effects [32]. In this context, antioxidant potential acquired as an inherent activity to polyphenolic compounds is accepted as the leading mode of action of lignin-like compounds [33].…”

Water-Soluble Alkali Lignin as a Natural Radical Scavenger and Anticancer Alternative

“…There is also information about the antioxidant, antiviral, antimicrobial, anticoagulant, and immune modulator capabilities of lignin and its derivatives [ 26 , 27 , 28 , 29 ]. Due to their biodegradability and biocompatibility, lignins possess characteristic marks to be involved in nanomedicine as precursors for the development of drug-delivery system(s) [ 30 , 31 ], but additional studies on their effect on intracellular homeostasis have to be performed.…”