Physicochemical and Biopharmaceutical Controllability of New Self-Assembled Fatty Acid Conjugated Leuprolide for the Enhanced Anticancer Activity

Chemical acylation of pea protein isolate hydrolysate with fatty acid N-hydroxysuccinimide esters: Effect on structure and functional properties

Applications of pea protein in the food industry have been greatly restricted by its poor functional properties. In order to solve this problem, a novel technique combining enzymatic hydrolysis and fatty acid acylation has been applied in this work to construct a pea protein-fatty acid covalent complex that aims to improve its functional properties. The processed pea protein with increased water solubility tends to decrease the chance of self-aggregation. Additionally, emulsifying and antioxidant properties have also been found after this process. On top of that, the modified pea protein has been characterized by Fourier transform infrared and circular dichroism spectroscopy. These results demonstrate that these properties were mainly caused by the acylation of the amino group from hydrolyzed pea protein and the carboxyl group from the fatty acid. The enzymatic hydrolysis/fatty acid acylation research provides insights into manufacturing high-quality functional lipoproteins from inexpensive pea protein for the food industry.

Self-assembled nanonization of fatty acid-conjugated vaccine antigen for enhanced thermal stability

The aim of this study was to evaluate the enhanced thermal stability and physicochemical properties of fattigated vaccine antigens. High molecular weight influenza hemagglutinin (Heg) was used as a model antigen because of low heat stability requiring cold chamber. Heg was conjugated with long-chain oleic acid (C18) and short-chain 3-decenoic acid (C10) to prepare fattigated Heg. Circular dichroism analysis revealed no significant changes in the three-dimensional structure post-conjugation. In the liquid state, the fattigated Heg was self-assembled into nanoparticles (NPs) due to its amphiphilic nature, with sizes of 136.27 ± 12.78 nm for oleic acid-conjugated Heg (HOC) and 88.73 ± 3.27 nm for 3-decenoic acid-conjugated Heg (HDC). Accelerated thermal stability studies at 60 °C for 7 days demonstrated that fattigated Heg exhibited higher thermal stability than Heg in various liquid or solid states. The longer-chained HOC showed better thermal stability than HDC in the liquid state, attributed to increased hydrophobic interactions during self-assembly. In bio-mimicking liquid states at 37 °C, HOC exhibited higher thermal stability than Heg. Furthermore, solid-state HOC with cryoprotectants (trehalose, mannitol, and Tween® 80) had significantly increased thermal stability due to reduced exposure of protein surface area via nanonization behavior. The current fattigation platform could be a promising strategy for developing thermostable nano vaccines of heat-labile vaccine antigens.

Nanonization and Deformable Behavior of Fattigated Peptide Drug in Mucoadhesive Buccal Films

This study was tasked with the design of mucoadhesive buccal films (MBFs) containing a peptide drug, leuprolide (LEU), or its diverse nanoparticles (NPs), for enhanced membrane permeability via self-assembled nanonization and deformable behavior. An LEU-oleic acid conjugate (LOC) and its self-assembled NPs (LON) were developed. Additionally, a deformable variant of LON (d-LON) was originally developed by incorporating l-α-phosphatidylcholine into LON as an edge activator. The physicochemical properties of LON and d-LON, encompassing particle size, zeta potential, and deformability index (DI), were evaluated. MBFs containing LEU, LOC, and NPs (LON, d-LON) were prepared using the solvent casting method by varying the ratio of Eudragit RLPO and hydroxypropyl methylcellulose, with propylene glycol used as a plasticizer. The optimization of MBF formulations was based on their physicochemical properties, including in vitro residence time, dissolution, and permeability. The dissolution results demonstrated that the conjugation of oleic acid to LEU exhibited a more sustained LEU release pattern by cleaving the ester bond of the conjugate, as compared to the native LEU, with reduced variability. Moreover, the LOC and its self-assembled NPs (LON, d-LON), equivalent to 1 mg LEU doses in MBF, exhibited an amorphous state and demonstrated better permeability through the nanonization process than LEU alone, regardless of membrane types. The incorporation of lauroyl-L-carnitine into the films as a permeation enhancer synergistically augmented drug permeability. Most importantly, the d-LON-loaded buccal films showed the highest permeability, due to the deformability of NPs. Overall, MBF-containing peptide NPs and permeation enhancers have the potential to replace parenteral LEU administration by improving LEU druggability and patient compliance.

Supramolecular Nanostructures for the Delivery of Peptides in Cancer Therapy

Supramolecular nanostructured based delivery systems are emerging as a meaningful approach in the treatment of cancer, offering controlled drug release and improved therapeutic efficacy. The self-assembled structures can be small molecules, polymers, peptides, or proteins, which can be used and functionalized to achieve tailored release and target specific cells, tissues, or organs. These structures can improve the solubility and stability of drugs having low aqueous solubility by encapsulating and protecting them from degradation. Alongside, peptides as natural biomolecules have gained increasing attention as potential candidates in cancer treatment because of their biocompatibility, low cytotoxicity, and high specificity toward tumor cells. The amino acid sequences in peptide molecules are tunable, efficiently controlling the morphology of peptide-based self-assembled nanosystems and offering flexibility to form supramolecular nanostructures (SNs). It is evident from the current literature that the supramolecular nanostructures based delivery of peptide for cancer treatment hold great promise for future cancer therapy, offering potential strategies for personalized medicine with improved patient outcomes. SIGNIFICANCE STATEMENT: This review focuses on fundamentals and various drug delivery mechanisms based on SNs. Different SN approaches and recent literature reviews on peptide delivery are also presented to the readers.

Thymol-Modified Oleic and Linoleic Acids Encapsulated in Polymeric Nanoparticles: Enhanced Bioactivity, Stability, and Biomedical Potential

Unsaturated fatty acids, such as oleic acid (OA) and linoleic acid (LA), are promising antimicrobial and cytostatic agents. We modified OA and LA with thymol (TOA and TLA, respectively) to expand their bioavailability, stability, and possible applications, and encapsulated these derivatives in polymeric nanoparticles (TOA-NPs and TLA-NPs, respectively). Prior to synthesis, we performed mathematical simulations with PASS and ADMETlab 2.0 to predict the biological activity and pharmacokinetics of TOA and TLA. TOA and TLA were synthesized via esterification in the presence of catalysts. Next, we formulated nanoparticles using the single-emulsion solvent evaporation technique. We applied dynamic light scattering, Uv-vis spectroscopy, release studies under gastrointestinal (pH 1.2-6.8) and blood environment simulation conditions (pH 7.4), and in vitro biological activity testing to characterize the nanoparticles. PASS revealed that TOA and TLA have antimicrobial and anticancer therapeutic potential. ADMETlab 2.0 provided a rationale for TOA and TLA encapsulation. The nanoparticles had an average size of 212-227 nm, with a high encapsulation efficiency (71-93%), and released TOA and TLA in a gradual and prolonged mode. TLA-NPs possessed higher antibacterial activity against B. cereus and S. aureus and pronounced cytotoxic activity against MCF-7, K562, and A549 cell lines compared to TOA-NPs. Our findings expand the biomedical application of fatty acids and provide a basis for further in vivo evaluation of designed derivatives and formulations.

Roles of Fatty Acid Chain Length and Enzyme-Oriented Drug Controlled Release from pH-Triggering Self-Assembled Fatty Acid Conjugated Quetiapine Nanosuspensions

Background

Quetiapine (QTP) is a first-line antipsychotic drug, but its therapeutic druggability and patient adherence were limited due to high oral dose strength, low bioavailability and physicochemical/biopharmaceutical issues.

Purpose

To investigate the roles of fatty acid chain length and enzyme-oriented QTP controlled release from pH-triggering self-assembled fatty acid conjugated QTP nanosuspensions (NSPs).

Methods

QTP was conjugated with different chain length fatty acids (C10-decanoic acid, C14-myristic acid, C18-stearic acid) to obtain QTP-fatty acid conjugates (QFCs: QD, QM, QS) by exploiting 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/4-dimethylaminopyridine (EDC/DMAP) conjugation chemistry. Then, the solubility, partitioning coefficient (log P), cell viability and cleavage kinetics of QFCs were evaluated. The pH-triggering self-assembled behaviors of QFCs to form QTP-fatty acid NSPs (QDN, QMN, QSN) by varying pH, QFC concentration and proton-to-QTP ratios were characterized. The morphological images, critical micelle concentration (CMC), physicochemical properties and enzyme-oriented QTP controlled release of NSPs were examined.

Results

Three QFCs were synthesized with different chain length fatty acids from QTP after desalting fumarate from QTP fumarate. The pH, QFC concentration and proton-to-quetiapine molar ratio could influence physicochemical properties and nanonization behaviors of QFCs. All three QFCs showed no effect on the viability of myoblast cells. The pH-triggering self-assembly of amphiphilic QFCs to form nanoparticles (NPs) occurred as the amine moiety of QTP was readily ionized in a strongly acidic environment (pH 1.2). Interestingly, the longer the fatty acid chain length, the lower water solubility, the higher log P (lipophilicity) and the smaller NP particle size were observed. The conversion rate of QFCs to liberate QTP by esterase in human plasma and liver S9 fractions was also inversely proportional to the fatty acid carbon chain length. Interestingly, the freeze-dried QMN showed the esterase-oriented controlled release of QTP over one month, unlike the initial burst release of QDN or the slowly delayed release pattern of QSN.

Conclusion

A new pH-triggering self-assembled nanonization platform was developed using different chain length fatty acid conjugated QTP in low pH environment. By varying fatty acid chain length, the enzyme-oriented QTP controlled release dosage form was challenged to enhance the therapeutic effectiveness of QTP.