Obesity is a chronic condition characterized by excessive fat accumulation, which disrupts the body's normal physiological processes. Obesity can be described as a multifactorial chronic illness that culminates due to a combination of various physiological (genetics, behavior, psychology) and environmental (sociocultural influence) elements [1]. Imbalance between energy consumption and expenditure, particularly in genetically susceptible individuals, can lead to the peculiar accumulation of fat in white adipose tissue, a hallmark of obesity. Obesity raises the chances of numerous diseases that are linked with high morbidity and mortality. It increases the need for medical treatments and surgical procedures to treat obesity and its associated comorbidities. Dozens of health conditions are associated with obesity, either directly or indirectly [2]. Altered glucose metabolism due to obesity has been associated with the expansion of hypertension, type 2 diabetes, and cardiovascular complications. Increased risk of gall bladder disease, gallstone formation, and osteoarthritis has been observed at a BMI ≥25, and these complications are more experienced by obese persons in comparison to lean counterparts [3]. Moreover, obesity has been linked with multiple cancers.

Although dietary and lifestyle alterations are independently effective in combating obesity, these changes are often difficult to sustain, as evidenced by the common observation of weight regain with slight ease. Consequently, numerous USFDA-approved anti-obesity drugs have made their presence in the market, with several other drugs currently in the pipeline [4]. Instead of targeting the pathophysiology of obesity, existing anti-obesity drugs function by suppressing appetite or stimulating the feeling of satiety. But a lot of these drugs have been linked with serious cardiovascular or mental health issues, which emphasizes the importance of other treatment alternatives [5].

PPARγ has also attracted considerable interest from researchers studying obesity due to its role in differentiating preadipocytes into mature adipocytes. The mechanism by which PPARγ exerts its control over lipogenesis and adipocyte differentiation involves the transcriptional regulation of genes such as lipase, acyl-CoA synthetase, fatty acid translocase (CD36), and fatty acid transport protein through various microRNAs. MicroRNA (miRNA) refers to small, non-coding RNA molecules that are 21–23 nucleotides in length. The primary functions in which miRNAs are involved are RNA silencing and post-transcriptional regulation of gene expression [6]. miRNAs typically repress the expression of targeted mRNA by reducing its stability and/or translation.

Various pathological and physiological conditions, like proliferation of cells, tissue development, energy metabolism, apoptosis, tumorigenesis, and immunological response, are influenced by miRNAs through their impact on targeted mRNAs. MiR-425, miR-143, miR-103, miR-200, miR-17-92 cluster, miR-27, and miR-29 are some of the miRNAs experimentally established as regulators of adipogenesis in mammalian adipose tissue. From the perspective of a potential anti-obesity therapy, miR-425 draws significant attention [7]. A study identified miR-425 (PPARγ-controlled regulatory miRNA) as a potent regulator of adipogenesis and adipolysis in adipocytes. It was reported that overexpression of miR-425 in mice helped to induce obesity using high-fat diet by enhancing the accumulation of body fat and downregulation of miR-425 by silencing prevents the obesity model induction. This study confirmed the use of silencing of miR-425 in prevention as well as treatment of obesity. Furthermore, silencing of miR-425 assists in the prevention of differentiation of adipocytes, hinders lipogenesis, promotes lipolysis, intracellular fat mobilization, and also elevates lipid oxidation. Therefore, anti-miR-425 was selected as a therapeutic for treatment of obesity as it works on different pathways of prevention and treatment of obesity. The critical regulatory role of miR-425 in governing adipogenesis and adipolysis, by concurrently stimulating multiple directional targets, was established in this study.

Since naked miRNA lacks biomembrane permeability, it is readily broken down by RNases in the blood and extracellular space. Viral vectors, which are frequently employed as tools for gene transfection, have the potential to randomly integrate into the host genome. Because of the potential for mutations and stimulation of immunogenicity, the use of viral vectors is highly restricted [8]. Massive efforts were undertaken to establish a non-viral and therapeutically applicable method for RNAi intracellular transfection. Liposomes are effective delivery methods that have already reached the market as lipid-based delivery vectors for siRNAs. Although lipid nanoparticles for miRNA delivery for various diseases are also in research, they are showing toxic effects due to the use of cationic lipids [9]. Even cationic polymeric structures showed significant promise for RNAi delivery. PAMAM dendrimers are synthetic, highly branched, and uniformly dispersed (monodisperse) macromolecules with definite structures and compositions. Terminal branches of PAMAM dendrimers functionalized with -NH2 group are typically employed for the delivery of miRNA into cells, as it enhances the endosomal escape of dendrimeric complex via the “proton-sponge” effect [[10], [11], [12]]. Meanwhile, its larger cationic charge restricts its in vivo application due to its toxicity. Therefore, there remains an unmet need for lipid-based cytosolic delivery systems capable of loading gene or RNAi therapeutics, which are non-toxic and can be used to target obesity. Therefore, we have used adipose homing peptide (AHP) that specifically binds to prohibitin in white fat tissue [13].

The proposed nanoformulation, named “Lipodendriplex,” will consist of an anti-miR dendriplex incorporated into an anionic liposomal vesicle. Moreover, positively charged Anti-miR Dendriplex will not be in direct contact with cell membranes and proteins to reduce the side effects due to its cationic nature, and anionic targeted liposomes will deliver the complex into the cells by receptor-based endocytosis. AHP-lipid conjugate was prepared to target the adipose tissue by binding to the prohibitin ligand. AHP-lipid conjugated lipodendriplex was prepared and characterized for particle size, PDI, zeta potential, entrapment efficiency, and SEM analysis. The in vitro safety of lipodendriplex was evaluated using cytocompatibility and hemocompatibility assays, and its in vivo safety was assessed through hematological and histopathological parameters. The efficacy of lipodendriplex for treating obesity was assessed in differentiated adipocytes and high-fat diet-induced obese mice by various parameters, such as reduction in body weight, organ weight, lipid profiling, mRNA, and protein expression.