Impact of Anti-PEG IgM Induced via the Topical Application of a Cosmetic Product Containing PEG Derivatives on the Antitumor Effects of PEGylated Liposomal Antitumor Drug Formulations in Mice.

Poly(ethylene glycol) (PEG) is used in many common products, such as cosmetics. PEG, however, is also used to covalently conjugate drug molecules, proteins, or nanocarriers, which is termed PEGylation, to serve as a shield against the natural immune system of the human body. Repeated administration of some PEGylated products, however, is known to induce anti-PEG antibodies. In addition, preexisting anti-PEG antibodies are now being detected in healthy individuals who have never received PEGylated therapeutics. Both treatment-induced and preexisting anti-PEG antibodies alter the pharmacokinetic properties, which can result in a subsequent reduction in the therapeutic efficacy of administered PEGylated therapeutics through the so-called accelerated blood clearance (ABC) phenomenon. Moreover, these anti-PEG antibodies are widely reported to be related to severe hypersensitivity reactions following the administration of PEGylated therapeutics, including COVID-19 vaccines. We recently reported that the topical application of a cosmetic product containing PEG derivatives induced anti-PEG immunoglobulin M (IgM) in a mouse model. Our finding indicates that the PEG derivatives in cosmetic products could be a major cause of the preexistence of anti-PEG antibodies in healthy individuals. In this study, therefore, the pharmacokinetics and therapeutic effects of Doxil (doxorubicin hydrochloride-loaded PEGylated liposomes) and oxaliplatin-loaded PEGylated liposomes (Liposomal l-OHP) were studied in mice. The anti-PEG IgM antibodies induced by the topical application of cosmetic products obviously accelerated the blood clearance of both PEGylated liposomal formulations. Moreover, in C26 tumor-bearing mice, the tumor growth suppressive effects of both Doxil and Liposomal l-OHP were significantly attenuated in the presence of anti-PEG IgM antibodies induced by the topical application of cosmetic products. These results confirm that the topical application of a cosmetic product containing PEG derivatives could produce preexisting anti-PEG antibodies that then affect the therapeutic efficacy of subsequent doses of PEGylated therapeutics.

Acid-Sensitive Sheddable PEGylated, Mannose-Modified Nanoparticles Increase the Delivery of Betamethasone to Chronic Inflammation Sites in a Mouse Model.

Inflammation is implicated in a host of chronic illnesses. Within these inflamed tissues, the pH of the microenvironment is decreased and immune cells, particularly macrophages, infiltrate the area. Additionally, the vascular integrity of these sites is altered with increased fenestrations between endothelial cells. These distinctive properties may be exploited to enhance targeted delivery of anti-inflammatory therapies. Using a mouse model of chronic inflammation, we previously showed that acid-sensitive sheddable PEGylation increases the distribution and retention of nanoparticles in chronic inflammation sites. Here we demonstrated that surface modification of the acid-sensitive sheddable PEGylated nanoparticles with mannose, a ligand to mannose receptors present in chronic inflammation sites, significantly increases the targeted delivery of the nanoparticles to these areas. Furthermore, we showed that the acid-sensitive sheddable PEGylated, mannose-modified nanoparticles are able to significantly increase the delivery of betamethasone-21-acetate (BA), a model anti-inflammatory compound, to chronic inflammation sites as compared to free BA. These results highlight the ability to engineer formulations to target chronic inflammation sites by exploiting the microenvironment of these regions.

Tumor-Associated Macrophage-Mediated Targeted Therapy of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer. TNBC is often infiltrated with a large number of macrophages, which in turn promote tumor growth and metastasis. In this study, tumor-associated macrophages (TAMs) were exploited as a target to deliver doxorubicin (DOX), a chemotherapeutic agent, to TNBC using nanoparticles surface-functionalized by (i) acid-sensitive sheddable PEGylation and (ii) modifying with mannose (i.e., DOX-AS-M-PLGA-NPs). In mice with orthotopic M-Wnt triple-negative mammary tumors, a single intravenous injection of DOX-AS-M-PLGA-NPs significantly reduced macrophage population in tumors within 2 days, and the density of the macrophages recovered slowly. Repeated injections of DOX-AS-M-PLGA-NPs can help maintain the population of the macrophages at a lower level. In M-Wnt tumor-bearing mice that were pretreated with zoledronic acid to nonselectively deplete macrophages, the TAM-targeting DOX-AS-M-PLGA-NPs were not more effective than the DOX-AS-PLGA-NPs that were not surface-modified with mannose and thus do not target TAMs in controlling tumor growth. However, in M-Wnt tumor-bearing mice that were not pretreated with zoledronic acid, the TAM-targeting DOX-AS-M-PLGA-NPs were significantly more effective than the nontargeting DOX-AS-PLGA-NPs in controlling the tumor growth. The AS-M-PLGA-NPs or other nanoparticles surface-functionalized similarly, when loaded with a chemotherapeutic agent commonly used in adjuvant therapy of TNBC, may be developed into targeted therapy for TNBC.

Treatment-induced and Pre-existing Anti-peg Antibodies: Prevalence, Clinical Implications, and Future Perspectives.

Polyethylene glycol (PEG) is a versatile polymer that is used in numerous pharmaceutical applications like the food industry, a wide range of disinfectants, cosmetics, and many commonly used household products. PEGylation is the term used to describe the covalent attachment of PEG molecules to nanocarriers, proteins and peptides, and it is used to prolong the circulation half-life of the PEGylated products. Consequently, PEGylation improves the efficacy of PEGylated therapeutics. However, after four decades of research and more than two decades of clinical applications, an unappealing side of PEGylation has emerged. PEG immunogenicity and antigenicity are remarkable challenges that confound the widespread clinical application of PEGylated therapeutics - even those under clinical trials - as anti-PEG antibodies (Abs) are commonly reported following the systemic administration of PEGylated therapeutics. Furthermore, pre-existing anti-PEG Abs have also been reported in healthy individuals who have never been treated with PEGylated therapeutics. The circulating anti-PEG Abs, both treatment-induced and pre-existing, selectively bind to PEG molecules of the administered PEGylated therapeutics inducing activation of the complement system, which results in remarkable clinical implications with varying severity. These include increased blood clearance of the administered PEGylated therapeutics through what is known as the accelerated blood clearance (ABC) phenomenon and initiation of serious adverse effects through complement activation-related pseudoallergic reactions (CARPA). Therefore, the US FDA industry guidelines have recommended the screening of anti-PEG Abs, in addition to Abs against PEGylated proteins, in the clinical trials of PEGylated protein therapeutics. In addition, strategies revoking the immunogenic response against PEGylated therapeutics without compromising their therapeutic efficacy are important for the further development of advanced PEGylated therapeutics and drug-delivery systems.

The MEK 1/2 inhibitor PD98059 exhibits synergistic anti-endometrial cancer activity with paclitaxel in vitro and enhanced tissue distribution in vivo when formulated into PAMAM-coated PLGA-PEG nanoparticles.

Endometrial cancer is the most common gynecological cancer that affects the female reproductive organs. The standard therapy for EC for the past two decades has been chemotherapy and/or radiotherapy. PD98059 is a reversible MEK inhibitor that was found in these studies to increase the cytotoxicity of paclitaxel (PTX) against human endometrial cancer cells (Hec50co) in a synergistic and dose-dependent manner. Additionally, while PD98059 arrested Hec50co cells at the G0/G1 phase, and PTX increased accumulation of cells at the G2/M phase, the combination treatment increased accumulation at both the G0/G1 and G2/M phases at low PTX concentrations. We recently developed poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) modified with polyethylene glycol (PEG) and coated with polyamidoamine (PAMAM) (referred to here as PGM NPs) which have favorable biodistribution profiles in mice, compared to PD98059 solution. Here, in order to enhance tissue distribution of PD98059, PD98059-loaded PGM NPs were prepared and characterized. The average size, zeta potential, and % encapsulation efficiency (%EE) of these NPs was approximately 184 nm, + 18 mV, and 23%, respectively. The PD98059-loaded PGM NPs released ~ 25% of the total load within 3 days in vitro. In vivo murine studies revealed that the pharmacokinetics and biodistribution profile of intravenous (IV) injected PD98059 was improved when delivered as PD98059-loaded PGM NPs as opposed to soluble PD98059. Further investigation of the in vivo efficacy and safety of this formulation is expected to emphasize the potential of its clinical application in combination with commercial PTX formulations against different cancers.

Prednisolone-loaded PLGA microspheres. in vitro characterization and in vivo application in adjuvant-induced arthritis in mice.

This study aimed at preparation of a sustained-release steroidal treatment for chronic inflammatory conditions, such as rheumatoid arthritis. To achieve such a goal, biodegradable poly-lactide-co-glycolide prednisolone-loaded microspheres were prepared using o/w emulsion solvent evaporation method. Formulation parameters were adjusted so as to optimize the microsphere characteristics. The prepared microspheres exhibited smooth and intact surfaces, with average size range not exceeding 65 microm. The encapsulation efficiency percent of most microsphere formulations fell within the range of 25-68%. Drug release from these microspheres took place over 4 weeks, with near-to-zero-order patterns. Two successful formulations were chosen for the treatment of unilateral arthritis, induced in mice using Freund's complete adjuvant (FCA). Inflammatory signs of adjuvant arthritis included severe swelling of the FCA-injected limbs, in addition to many histopathological lesions. These included inflammatory cell infiltration, synovial hyperplasia, cartilage, and bone erosion. Parenteral administration of the selected formulae dramatically reduced the swelling of the FCA-injected limbs. In addition, histological examination revealed that the microsphere treatment protocol efficiently protected cartilages and bones of mice, injected with FCA initial and booster doses, from erosion. These results could not be achieved by a single prednisolone dose of 5 mg/kg.

Design, characterization and in vivo evaluation of modified release baclofen floating coated beads.

Baclofen is a centrally acting skeletal muscle relaxant approved by the US Food and Drug Administration (FDA) for the treatment of muscle spasticity, but the immediate release mode of administration and rapid absorption has been associated with adverse effects. The main objective of this study was to prepare modified release floating beads of baclofen in order to decrease the unwanted side effects. The beads were prepared using alginate and coated with Eudragit RS100, Eudragit L100 and cetyl alcohol. They were evaluated for their encapsulation efficiency, buoyance characteristics, morphology, and in vitro release. They have also been tested in vivo for their oral bioavailability and potential side effects. The prepared beads showed floating properties up to 12 h with different lag times ranging from 45.67 to 72.33 sec. Morphological evaluation using scanning electron microscopy (SEM) revealed that the coated beads show smooth with no pores or cracks surfaces. Real-time morphology of the beads during in vitro release testing was studied by the SEM. Optimized formulation of baclofen coated beads exhibited favorable mechanical properties, in addition, it provided extended baclofen release for up to 6 h. In addition, in vivo studies showed that the coated beads effectively decreased the hypotensive side effect associated with rapid plasma peaking from Baclofen® immediate-release tablets. In addition, there were significant differences between the values of Cmax, Tmax, and AUC0-24 of optimized modified release baclofen floating formulations when compared to Baclofen® immediate-release tablets.