The widespread concerns about the environmental problems caused by conventional plastic food packaging and food waste led to a growing effort to develop active and intelligent systems produced from renewable biodegradable polymers for food packaging applications. Among intelligent systems, the most widely used are pH indicators, which are generally based on a pH-sensitive dye incorporated into a solid support. The objective of this study was to develop new intelligent systems based on renewable biodegradable polymers and a new bio-inspired pH-sensitive dye. The structure of the dye was elucidated through FT-IR and 1D and 2D NMR spectroscopic analyses. UV-VIS measurements of the dye solutions at various pH values proved their halochromic properties. Their toxicity was evaluated through theoretical calculations, and no toxicity risks were found. The new anthocyanidin was used for the development of biodegradable intelligent systems based on chitosan blends. The obtained polymeric films were characterized through UV-VIS and FT-IR spectroscopy. Their thermal properties were assessed through a thermogravimetric analysis, which showed a better stability of chitosan–PVA–dye and chitosan–starch–dye films compared to those of chitosan–cellulose–dye films and the dye itself. The films’ sensitivity to pH variations was evaluated through immersion in buffer solutions with pH values ranging from 2 to 12, and visible color changes were observed.

Azelaic acid (AzA), a saturated dicarboxylic acid, is indicated for the treatment of acne vulgaris, rosacea, melasma, and post-inflammatory hyperpigmentation. Its antimicrobial, anti-inflammatory, and antimelanogenic properties support its use; however, its poor aqueous solubility and limited skin permeability constrain its optimal topical delivery. This review summarizes clinical evidence and advances in formulations—including conventional vehicles, polymeric/lipid nanocarriers, and deep eutectic solvent (DES) systems—to promote more effective and well-tolerated use. Across indications, 15–20% azelaic acid (AzA) formulations produced clinically meaningful improvements with mild, transient local irritation. For acne vulgaris, reductions in inflammatory and noninflammatory lesions were comparable to those of topical retinoids/adapalene, and tolerability was superior in some studies. For rosacea, the 15% gel formulation was comparable to metronidazole in reducing papules, pustules, and erythema while maintaining negligible systemic exposure. In melasma and other dyschromias, 20% cream demonstrated efficacy similar to hydroquinone, exhibiting a favorable safety profile. Advanced delivery systems, including liposomes, niosomes/ethosomes, nanostructured lipid carriers, microemulsions, nanosponges, and DES platforms, increased AzA solubilization, cutaneous deposition, and stability. This enabled dose-sparing strategies and improved adherence. Data on AzA cocrystals and ionic salts suggest additional control over release and irritation. AzA remains a versatile and well-tolerated dermatologic agent whose performance is strongly vehicle-dependent. Rational selection and engineering of carriers, particularly DES-integrated polymeric and lipid systems, can mitigate solubility and permeability limitations, enhance skin targeting, and reduce irritation in the treatment of acne and rosacea.

New technologies for the conversion of biomass into high-value chemicals, including polymers and plastics, is a must and a challenge. The development of green processes in the last decade involved a continuous increase of the interest towards the synthesis of polymers using in vitro biocatalysis. Among the remarkable diversity of new bio-based polymeric products meeting the criteria of sustainability, biocompatibility, and eco-friendliness, a wide range of polyesters with shorter chain length were obtained and characterized, targeting biomedical and cosmetic applications. In this review, selected examples of such specialty polymers are presented, highlighting the recent developments concerning the use of lipases, mostly in immobilized form, for the green synthesis of ε-caprolactone co-polymers, polyesters with itaconate or furan units, estolides, and polyesteramides. The significant process parameters influencing the average molecular weights and other characteristics are discussed, revealing the advantages and limitations of biocatalytic processes for the synthesis of these bio-based polymers.

Natural deep eutectic solvents (NADESs) are a sustainable, green option for extraction and reaction media in biorefineries and various chemical and biotechnological applications. Particularly, enzymatic reactions profit from NADES applications, as these solvents help to maintain high substrate solubility while improving both enzyme stability and efficiency. Recent studies confirmed that NADESs can perform multiple functions simultaneously, as reaction media for biocatalytic conversions, but also as substrates and catalysts for reactions, fulfilling the role of a reactive solvent. This study reports the beneficial effect of designed reactive natural deep eutectic solvents (R-NADESs) on the esterification activity and thermal stability of free and immobilized lipases in the synthesis of polyol- and carbohydrate-based biosurfactants. We manufactured and characterized 16 binary and ternary R-NADES systems with choline chloride (ChCl) as the hydrogen bond acceptor (HBA) and carbohydrate polyols; mono-, di-, and oligosaccharides; urea (U); N-methyl urea (MU); and water as the hydrogen bond donors (HBDs), in different combinations and molar ratios, most of which are reported for the first time in this paper. We determined their physicochemical, thermal, and molecular properties, including among others viscosity, polarizability, and the number of hydrogen bonds, and we showed that these properties are controlled by composition, molar ratio, molecular properties, temperature, and water content. Many lipases, both native and immobilized, showed high stability and remarkable catalytic performance in R-NADESs during esterification reactions.

Puerarin is a naturally occurring isoflavone with reported anticancer activity, yet its topical translation is constrained by limited stability and suboptimal dermal delivery. A Puerarin-loaded proniosomal gel was developed as a potential dermal delivery platform, and we performed an initial assessment of its antimelanoma activity and safety. The gel was produced by coacervation–phase separation using Span 60, Tween 80, phosphatidylcholine, and cholesterol. Physicochemical characterization included pH, entrapment efficiency, rheology, FTIR, DSC, and vesicle properties (DLS, PDI, ζ-potential). In silico geometry optimization and docking were carried out for melanoma-associated targets (MITF and DNMT3B). Biological effects were investigated in vitro on A375 melanoma cells using MTT, morphological analysis, and nuclear/mitochondrial staining, while irritation potential was evaluated in ovo by HET-CAM. The optimized formulation exhibited a skin-compatible pH and an entrapment efficiency of 62 ± 0.26%. DLS indicated a multimodal population, with a major number-weighted vesicle population in the 100–200 nm range, and a ζ-potential of −34.9 ± 0.14 mV. FTIR and DSC supported component incorporation without evidence of chemical incompatibility. The gel showed non-Newtonian, pseudoplastic, thixotropic flow, which is advantageous for topical use. Docking predicted meaningful affinities of Puerarin toward MITF and DNMT3B. The formulation reduced A375 viability in a dose-dependent manner (to 44.66% at 200 µg/mL) and, at higher concentrations, produced nuclear condensation and disruption of the mitochondrial network. HET-CAM classified the gel as non-irritant. The Puerarin-loaded proniosomal gel represents a promising topical platform with preliminary in vitro antimelanoma cytotoxic potential, warranting additional studies to validate skin delivery, efficacy, and safety.

Biocatalysis has developed in the last decades as a major tool for green polymer synthesis. The particular ability of lipases to catalyze the synthesis of novel polymeric materials has been demonstrated for a large range of substrates. In this work, novel functional oligoesters were synthesized from ε-caprolactone and D,L/L-malic acid by a green and sustainable route, using two commercially available immobilized lipases as catalysts. The reactions were carried out at different molar ratios of the comonomers in organic solvents, but the best results were obtained in solvent-free systems. Linear and cyclic oligomeric products with average molecular weights of about 1500 Da were synthesized, and the formed oligoesters were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The oligoester synthesis was not enantioselective in the studied reaction conditions. The operational stability of both biocatalysts (Novozyme 435 and GF-CalB-IM) was excellent after reutilization in 13 batch reaction cycles. The thermal properties of the reaction products were investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis. The presence of polar pendant groups in the structure of these oligomers could widen the possible applications compared to the oligomers of ε-caprolactone or allow the conversion to other functional materials.