Amphiphilic carboxylated cellulose-g-poly(l-lactide) copolymer nanoparticles for oleanolic acid delivery

Recent advances in the chemistry and biology of oleanolic acid and its derivatives

The pentacyclic triterpenes represent a significant class of plant bioactives with a variety of structures and a wide array of biological activities. These are biosynthetically produced via the mevalonate pathway although occasionally mixed pathways may also occur to introduce structural divergence. Oleanolic acid is one of the most explored bioactive from this class of compounds and possesses a broad spectrum of pharmacological and biological activities including liver protection, anti-cancer, atherosclerosis, anti-inflammation, antibacterial, anti-HIV, anti-oxidative, anti-diabetic etc. This review provides an overview of the latest research findings, highlighting the versatile medicinal and biological potential of oleanolic and its future prospects.

Targeted codelivery of doxorubicin and oleanolic acid by reduction responsive hyaluronic acid-based prodrug nano-micelles for enhanced antitumor activity and reduced toxicity

Chemotherapy remains one of the most commonly used strategies in cancer treatment but suffers from damages to healthy tissues and organs. How to precisely co-deliver two or more drugs with different mechanisms of action to the tumors for synergistic function is a challenge for chemotherapy. Herein, Oleanolic acid (OA)-conjugated Hyaluronic acid self-assembled nano-micelles loaded with Doxorubicin (DOX) (HSO NPs/DOX) were constructed for CD44 positive cancer targeted codelivery of DOX and OA. HSO NPs/DOX exhibited reduction triggered drug release under high concentration of glutathione, more efficient uptake by 4T1 breast cancer cells than free DOX leading to higher cytotoxicity, pro-apoptotic, and migration inhibitory activities against 4T1 cells. The ex vivo biodistribution experiment demonstrated more HSO NPs/DOX were accumulated in the tumor tissues than free DOX and less in the non-tumor tissues after injections in 4T1 tumor bearing mice. More importantly, synergistic anti-tumor effects of DOX and OA were obtained using HSO NPs/DOX in 4T1 breast tumor-bearing mice and toxicity of DOX to liver and heart were circumvented through regulating the Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Silent Information Regulator 1 (Sirt1) expressions. Taken together, HSO NPs/DOX may become a promising codelivery system for chemotherapeutics in cancer therapy.

Unlocking the Potential of Oleanolic Acid: Integrating Pharmacological Insights and Advancements in Delivery Systems

The growing interest in oleanolic acid (OA) as a triterpenoid with remarkable health benefits prompts an emphasis on its efficient use in pharmaceutical research. OA exhibits a range of pharmacological effects, including antidiabetic, anti-inflammatory, immune-enhancing, gastroprotective, hepatoprotective, antitumor, and antiviral properties. While OA demonstrates diverse pharmacological effects, optimizing its therapeutic potential requires overcoming significant challenges. In the field of pharmaceutical research, the exploration of efficient drug delivery systems is essential to maximizing the therapeutic potential of bioactive compounds. Efficiently delivering OA faces challenges, such as poor aqueous solubility and restricted bioavailability, and to unlock its full therapeutic efficacy, novel formulation strategies are imperative. This discussion thoroughly investigates different approaches and advancements in OA drug delivery systems with the aim of enhancing the biopharmaceutical features and overall efficacy in diverse therapeutic contexts.

A state-of-the-art review on plant-derived cellulose-based green hydrogels and their multifunctional role in advanced biomedical applications

The most prevalent carbohydrate on Earth is cellulose, a polysaccharide composed of glucose units that may be found in diverse sources, such as cell walls of wood and plants and some bacterial and algal species. The inherent availability of this versatile material provides a natural pathway for exploring and identifying novel uses. This study comprehensively analyzes cellulose and its derivatives, exploring their structural and biochemical features and assessing their wide-ranging applications in tissue fabrication, surgical dressings, and pharmaceutical delivery systems. The use of diverse cellulose particles as fundamental components gives rise to materials with distinct microstructures and characteristics, fulfilling the requirements of various biological applications. Although cellulose boasts substantial potential across various sectors, its exploration has predominantly unfolded within industrial realms, leaving the biomedical domain somewhat overlooked in its initial stages. This investigation, therefore, endeavors to shed light on the contemporary strides made in synthesizing cellulose and its derivatives. These innovative techniques give rise to distinctive attributes, presenting a treasure trove of advantages for their compelling integration into the intricate tapestry of biomedical applications.

Synthesis and catalytic performance of wood cellulose nanofibers grafted with polylactic acid in rare-earth complexes based on tetrazole carboxylic acids

Stannous octanoate [Sn(Oct)2] and 4-dimethylamino pyridine (DMAP) were used to catalyze the synthesis of amphiphilic cellulose-based graft copolymers, but the acute toxicity of tin ions and DMAP prompts the need for the application of less harmful catalysts. Herein, green catalyst complexes 1-3 [M(H0.5L)2(H2O)5]·2(H2O) (M = Sm, 1; M = Nd, 2; M = Eu, 3; H2L = 4-(3-(tetrazol-5-yl)pyridin-5-yl)benzoic acid) were synthesized, and their properties were systematically investigated. Single-crystal X-ray diffraction showed that the complexes possessed a zero-dimensional structure, while the thermogravimetry and scanning electron microscopy results confirmed their stability after heating at 110 °C for 10 h. Using complexes 1-3 and DMAP as the catalysts, CNFs were grafted with l-lactide via homogeneous ring-opening polymerization to form wood cellulose nanofibers grafted with l-lactide (WGLAs), and the effects of the ratio of wood cellulose nanofibers (WCNFs) to l-lactide ([AGU]/[LA]) and catalyst dosage were studied. The polymerization followed the coordination-insertion mechanism. Under comparable reaction conditions, the grafting ratio of WGLA-1 reached 84.7 %, and the grafting ratio of complex 1 was found to be higher than those achieved using DMAP. WGLAs demonstrated good thermal stability without cytotoxicity, and the residual catalysts in the WGLAs exhibited fluorescence characteristics. Overall, amphiphilic cellulose-based materials with fluorescence emission offered a promising modification strategy to prepare high-performance polymer composites for agriculture and biomedical application.

Synthesis approaches of amphiphilic copolymers for spherical micelle preparation: application in drug delivery

The formation of polymeric micelles in aqueous environments through the self-assembly of amphiphilic polymers can provide a versatile platform to increase the solubility and permeability of hydrophobic drugs and pave the way for their administration. In comparison to various self-assembly-based vehicles, polymeric micelles commonly have a smaller size, spherical morphology, and simpler scale up process. The use of polymer-based micelles for the encapsulation and carrying of therapeutics to the site of action triggered a line of research on the synthesis of various amphiphilic polymers in the past few decades. The extended knowledge on polymers includes biocompatible smart amphiphilic copolymers for the formation of micelles, therapeutics loading and response to external stimuli, micelles with a tunable drug release pattern, etc. Different strategies such as ring-opening polymerization, atom transfer radical polymerization, reversible addition-fragmentation chain-transfer, nitroxide mediated polymerization, and a combination of these methods were employed to synthesize copolymers with diverse compositions and topologies with the proficiency of self-assembly into well-defined micellar structures. The current review provides a summary of the important polymerization techniques and recent achievements in the field of drug delivery using micellar systems. This review proposes new visions for the design and synthesis of innovative potent amphiphilic polymers in order to benefit from their application in drug delivery fields.

Oleanolic Acid Complexation with Cyclodextrins Improves Its Cell Bio-Availability and Biological Activities for Cell Migration

Wound healing is a complex process to restore skin. Plant-derived bioactive compounds might be a source of substances for the treatment of wounds stalled in a non-resolving stage of wound healing. Oleanolic acid (OA), a pentacyclic triterpene, has shown favorable wound healing properties both in vitro and in vivo. Unfortunately, OA cannot be solubilized in aqueous media, and it needs to be helped by the use of dimethyl sulfoxide (DMSO). In this paper, we have shown that cyclodextrins (CDs) are a good alternative to DMSO as agents to deliver OA to cells, providing better features than DMSO. Cyclodextrins are natural macromolecules that show a unique tridimensional structure that can encapsulate a wide variety of hydrophobic compounds. We have studied the cyclodextrin-encapsulated form of OA with OA/DMSO, comparing their stability, biological properties for cell migration, and cell viability. In addition, detailed parameters related to cell migration and cytoskeletal reorganization have been measured and compared. Our results show that OA-encapsulateds compound exhibit several advantages when compared to non-encapsulated OA in terms of chemical stability, migration enhancement, and preservation of cell viability.

Biomaterials and Extracellular Vesicle Delivery: Current Status, Applications and Challenges

In this review, we will discuss the current status of extracellular vesicle (EV) delivery via biopolymeric scaffolds for therapeutic applications and the challenges associated with the development of these functionalized scaffolds. EVs are cell-derived membranous structures and are involved in many physiological processes. Naïve and engineered EVs have much therapeutic potential, but proper delivery systems are required to prevent non-specific and off-target effects. Targeted and site-specific delivery using polymeric scaffolds can address these limitations. EV delivery with scaffolds has shown improvements in tissue remodeling, wound healing, bone healing, immunomodulation, and vascular performance. Thus, EV delivery via biopolymeric scaffolds is becoming an increasingly popular approach to tissue engineering. Although there are many types of natural and synthetic biopolymers, the overarching goal for many tissue engineers is to utilize biopolymers to restore defects and function as well as support host regeneration. Functionalizing biopolymers by incorporating EVs works toward this goal. Throughout this review, we will characterize extracellular vesicles, examine various biopolymers as a vehicle for EV delivery for therapeutic purposes, potential mechanisms by which EVs exert their effects, EV delivery for tissue repair and immunomodulation, and the challenges associated with the use of EVs in scaffolds.

Cellulose Amphiphilic Materials: Chemistry, Process and Applications

In the last decade, amphiphilic cellulose (AC) is emerging as attractive biomaterial for different therapeutic use, due to its unique chemical and physical properties. Using it as alternative to synthetic polymers, AC opens up new avenues to prepare new bio-sustainable materials with low impact in the cellular environment. Herein, most recent methods to synthesize and processing AC materials from different sources—i.e., cellulose nanofibers, bacterial cellulose, cellulose derivatives—will be discussed. By an accurate optimization of morphology and surface chemistry, it is possible to develop innovative amphiphilic platforms, promising for a wide range of biomedical applications, from drug delivery to molecular/particle adsorption.

The novel nanocomplexes containing deoxycholic acid-grafted chitosan and oleanolic acid displays the hepatoprotective effect against CCl4-induced liver injury in vivo

Chemical liver injury threatens seriously human health, along with the shortage of efficiency and low-toxicity drugs. Herein, the novel oral nanocomplexes composed of deoxycholic acid-grafted chitosan and oleanolic acid were constructed to reverse the CCl₄-induced acute liver damage in mice. Results indicated core-shell nanocomplexes, maintained by the hydrophobic interaction between deoxycholic acid and oleanolic acid, could be dissociated in the intestine. Notably, the nanocomplexes possessed superior hepatoprotective effect in vivo, possibly due to the synergistic effect between grafted chitosan and oleanolic acid. Mechanism investigations suggested that nanocomplexes reversed CCl₄-induced liver injury through improving hepatic antioxidant capacity via NrF2/Keap1 pathway and regulating inflammation response via NF-κB signaling pathway. The novel oral nanocomplexes represent an effective strategy for chemical liver injury therapy.

Co-delivery of cisplatin and oleanolic acid by silica nanoparticles-enhanced apoptosis and reverse multidrug resistance in lung cancer

Multidrug resistance (MDR) of chemotherapy is one of the significant concerns in cancer therapy. Here in our study, cisplatin (DDP) and oleanolic acid (OA) were co-loaded in mesoporous silica nanoparticles (Nsi) to construct DDP/OA-Nsi and solve the DDP-resistance in lung cancer therapy. The cytotoxicity and apoptosis assays demonstrated that in DDP-resistant A549/DDP cells, the cytotoxicity of DDP/OA-Nsi was significantly higher than that of free DDP or DDP single delivery system (DDP-Nsi). The intracellular drug accumulation study revealed that the intracellular DDP concentration in the DDP/OA-Nsi group was also higher than that in free DDP and DDP-Nsi groups. In the A549/DDP xenograft tumor model, DDP/OA-Nsi showed the best anticancer effect. In summary, DDP/OA-Nsi was a promising drug delivery system to solve MDR in lung cancer therapy.

Development and Evaluation of Oleanolic Acid Dosage Forms and Its Derivatives

Oleanolic acid is a pentacyclic triterpenoid compound that exists widely in medicinal herbs and other plants. Because of the extensive pharmacological activity, oleanolic acid has attracted more and more attention. However, the structural characteristics of oleanolic acid prevent it from being directly made into new drugs, which limits the application of oleanolic acid. Through the application of modern preparation techniques and methods, different oleanolic acid dosage forms and derivatives have been designed and synthesized. These techniques can improve the water solubility and bioavailability of oleanolic acid and lay a foundation for the new drug development. In this review, the recent progress in understanding the oleanolic acid dosage forms and its derivatives are discussed. Furthermore, these products were evaluated comprehensively from the perspective of characterization and pharmacokinetics, and this work may provide ideas and references for the development of oleanolic acid preparations.

Nanocrystallized Oleanolic Acid Better Inhibits Proliferation, Migration and Invasion in Intracranial Glioma via Caspase-3 Pathway

Glioma associates with high malignancy and poor prognosis for traditional treatment. Oleanolic acid (OA) has been confirmed to have an inhibitory effect on different kinds of tumors, while accompanying with low efficiency because of its large molecular mass and low solubility. Nanoliposome is an appropriate drug delivery system that can compensate for the limitations of traditional insoluble drugs, involving improvement of their solubility, stability and lipophilicity. In the present study, we comprised of OA covered with nanoliposomes, named OA^nano, to observe antitumor effects on U87 glioma cells. The results showed that OA^nano raised the solubility and oil-water partition coefficient. OA^nano suppressed proliferation of U87 glioma cells, and also had an anticancer effect on U87 glioma cells, which was found to be higher than that of OA. Moreover, treatment with OA^nano induced apoptosis and degraded migration ability by caspase-3 pathway. In conclusion, our results demonstrated that OA covered with nanoliposomes led to enhanced anticancer effects by suppressing proliferation, migration and invasion abilities. The findings may provide a reliable reference for development of new anti-cancer drugs.