BACKGROUND:Lung infections affect over 80% of adults with cystic fibrosis, with Pseudomonas aeruginosa being a leading pathogen. Although antibiotics are frequently nebulized as standard treatments, the physicochemical environment of the diseased lung often limits their diffusion and overall effectiveness. Our previous studies showed polyelectrolyte surfactants (PS) to be a promising delivery system for cationic antimicrobials in vitro. This study seeks to expand that knowledge by evaluating their potential for nebulized delivery. METHODS:To achieve this, we evaluated their size and antimicrobial activity following nebulization; in vitro toxicity against epithelial cells and erythrocytes; and biodistribution and expression of inflammation markers following administration to healthy mice. RESULTS:The nanoparticle formulation exhibited a mucolytic effect on an artificial mucus model of cystic fibrosis mucus. Following nebulization, nanoparticles retained both their size and biological activity. Additionally, they displayed no observable toxicity in vitro against either human lung epithelial cells or erythrocytes; instead, epithelial cells treated with PS-based nanoparticles showed increased cell viability. Following administration of these formulations to mice via inhalation, over 70% of the recovered nanoparticles were retained in the lungs 24 h after treatment, with a small fraction being uniformly distributed to other tissues. A screen of key inflammatory cytokines revealed that inhalation treatment led to a slight increase of IL-6 in the liver and IL-18 in the spleen. These increases seem to be consistent with a minor inflammatory response. CONCLUSION:Overall, the results suggest that PS are a promising nanotechnology for the pulmonary delivery of cationic drugs.

Plasma membrane fusion and resealing play essential roles in diverse biological processes, including embryogenesis, morphogenesis, tissue repair, and cancer metastasis. Certain polymeric surfactants, including poly(ethylene glycol) (PEG) and triblock poly(alkylene oxides) like Poloxamer 188 (P188), are known to modify cell membrane biophysical properties. This has enabled applications such as PEG fusion for severed nerves and P188-mediated muscle tissue repair. Similar to P188, tyrosine-derived triblock copolymers (TyPS) form self-assembled nanospheres that can reversibly insert into phospholipid monolayers and cell plasma membranes. The effects of phospholipid head group polarity on the insertion of TyPS into Langmuir phospholipid monolayers are examined here. The hydrophobic blocks of the polymeric surfactants are found to provide the primary driving force for insertion in the phospholipid membranes. The impact of the TyPS, PEG, and P188, alone and in combination, on membrane fusion in normal (L929 mouse fibroblast) and transformed (MDA-MB-231 human breast cancer) cells is then determined using in vitro cell culture methods. The cell culture studies demonstrate that PEG induces fusion in both cell lines and reveal that the combination of PEG and P188 has a strong positive synergistic effect on cell fusion. In contrast, the TyPS exhibits strong anti-fusion properties, inhibiting both spontaneous and PEG-enhanced fusion. P188 has a weak antifusion effect compared to TyPS. The fusogenic or antifusogenic behaviors of the polymeric surfactants correlate with their thermodynamic Hansen solubility parameters, and the synthetic tunability of the TyPS enables access to a far greater range of hydrophobicities than the available commercial Poloxamers. These findings suggest that mixtures of PEG and P188 may have the potential to enhance tissue repair and hybridoma output for monoclonal antibody production, while the TyPS may have the potential to inhibit metastatic cancers.

Nearly 80% of cystic fibrosis patients are affected by persistent lung infections, with Pseudomonas aeruginosa being one of the major culprits. Treatment of P. aeruginosa is further complicated by its ability to form biofilms. Anionic compounds within the biofilm and thick cystic fibrosis mucus interact with cationic antimicrobials, hindering treatment efficacy. In this study, we investigated the treatment of lung infections by delivering antimicrobials via polyelectrolyte surfactants that are composed of an anionic poly(alkylacrylic acid) backbone with grafted polyetheramine pendent chains. When combined with cationic antimicrobials, they self-assemble into nanoparticles via electrostatic interactions. We assessed the role of backbone chemistry and graft density on nanoparticle physical properties and evaluated the antimicrobial activity of these formulations against planktonic and biofilm cultures of P. aeruginosa strains derived from clinical isolates. All synthesized polyelectrolyte surfactants demonstrated high levels of antimicrobial encapsulation, with the extent of drug bound corresponding to the calculated hydrophilic-lipophilic balance values. We observed significantly increased antimicrobial activity against planktonic cultures using nanoformulations containing one of the polyelectrolyte surfactants, PMAA-g-10%J. In contrast, all tested nanoformulations retained, but did not increase, activity against biofilms. By monitoring membrane potentials and nanoparticle uptake, it was found that the nanoparticles directly associate with the bacterial cell membranes, which may enhance drug delivery and underlie the improved activity against the planktonic bacteria. In conclusion, we provide a proof of concept for the design of polyelectrolyte surfactants for the nanoencapsulation and delivery of cationic drug cargoes against P. aeruginosa infections.

Hypothesis: The design of biodegradable tyrosine-derived polymeric surfactants (TyPS) through the use of calculated thermodynamic parameters could lead to phospholipid membrane surface modifiers capable of con-trolling cellular properties such as viability. Delivery of cholesterol by TyPS nanospheres into membrane phospholipid domains could provide further controlled modulation of membrane physical and biological properties.Experiment: Calculated Hansen solubility parameters ( partial differential T) and hydrophile:lipophile balances (HLB) were applied to design and synthesize a small family of diblock and triblock TyPS with different hydrophobic blocks and PEG hydrophilic blocks. Self-assembled TyPS/cholesterol nanospheres were prepared in aqueous media via co -precipitation. Cholesterol loading and Langmuir film balance surface pressures of phospholipid monolayers were obtained. TyPS and TyPS/cholesterol nanosphere effects on human dermal cell viability were evaluated by cell culture using poly(ethylene glycol) (PEG) and Poloxamer 188 as controls.Findings: Stable TyPS nanospheres incorporated between 1% and 5% cholesterol. Triblock TyPS formed nano -sphere with dimensions significantly smaller than diblock TyPS nanospheres. In accord calculated thermody-namic parameters, cholesterol binding increased with increasing TyPS hydrophobicity. TyPS inserted into phospholipid monolayer films in a manner consistent with their thermodynamic properties and TyPS/cholesterol nanospheres delivered cholesterol into the films. Triblock TyPS/cholesterol nanospheres increased human dermal cell viability, which was indicative of potentially beneficial TyPS effects on cell membrane surface properties.

Hypothesis: Blending amphiphilic triblock (A-B-A) and diblock (A-B) copolymers comprised of the same hydrophobic tyrosine-derived oligomeric B-block and hydrophilic poly(ethylene glycol) methyl ether (mPEG) A-block can provide highly tunable self-assembled nanosphere particle sizes suitable for biomedical applications. Experiment: Triblock and diblock copolymers were synthesized via carbodiimide chemistry and were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The amount of free PEG present in the purified copolymers was determined using a standard addition calibration curve and GPC peak deconvolution methods. Nanospheres were prepared by co-precipitation of each copolymer and of copolymer blends over a range of mole ratios. Nanospheres were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and % polymer recovery post-preparation. Finding: Precise synthesis control produced triblock and diblock copolymers with narrow molecular weight distributions and minimal residual reactants. Self-assembled nanosphere particle sizes were 33 nm for the triblock and 129 nm for the diblock, and the size of their blends increased continuously as a function of mole ratio within that biomedically relevant range. Addition of unreacted PEG had minimal impact on either triblock or diblock nanosphere particle sizes whereas addition of unreacted oligomeric B-block increased nanosphere sizes. (C) 2022 Elsevier Inc. All rights reserved.

The biocompatibility and anticancer effect of hydroxyapatite nanoparticles (HAPNs) are compelling and promising in cancer nanomedicine. However, the essential role of fetal bovine serum (FBS) in a biological environment possibly determining the state of agglomeration and intracellular fate of HAPNs (length: ~ 60 nm; width: ~ 20 nm) has never been studied. Here, we investigated the importance of FBS in agglomeration and cell response of HAPNs in human osteosarcoma MG-63 cells. Protein adsorption on the surface of HAPNs after mixing with different concentrations of FBS was confirmed using transmission electron microscope (TEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, quartz crystal microbalance with dissipation (QCM-D), and thermogravimetric analysis (TG). The adsorption of serum protein improved dispersed state and stabilization of HAPNs, which was evidenced by dynamic light scattering (DLS), inverted microscope, and scanning electron microscope (SEM). More specifically, the agglomerate size of HAPNs in cell culture medium without FBS was above 1400 nm, while the agglomerate size of HAPNs with 10% FBS was decreased to about 200 nm and maintained for at least five days. Meanwhile, serum protein adsorption on HAPN surface enhanced cellular uptake and anticancer efficacy of HAPNs in MG-63 cells.

54 AQUEOUS POLYAMIDE DISPERSION 4,810,772 3/1989 Leoni et al.. COMPOSITION 4.820,765 4/1989 Whyzmuzis. 4,873,311 10/1989 Bornack, Jr. et al.. 75 Inventors: Chase J. Boudreaux, Cordova, Tenn.; 4,894,433 1/1990 Bornack, Jr. et al. . Timothy Vogel; David I. Devore, both 4.912, 196 3/1990 Leoni et al.. 4.914,162 4/1990 Leoni et al. . of Langhorne, Pa.; Reimar Heucher, 4973,519 11 2f1990 Tortorici et al. . Pulheim, Germany; Stephen A. 4,992,500 2/1991 Klauck .................................... 524/270 Fischer, Yardley, Pa.; Kartar S. Arora, 5,025,043 6/1991 Smith ... ... 523/326 Racine, Wis. 5,109,054 4/1992 Smith ...................................... 524/514 5,126,429 6/1992 Köhler et al.. 73 Assignee: Cognis Corporation, Gulph Mills, Pa. 5,138,027 8/1992 Van Beek. 5,277,978 1/1994 Feustel et al.. 5,344,872 9/1994 Debord et al.. 21 Appl. No.: 09/163,143

The dissipative particle dynamics (DPD) simulation technique is a coarse-grained (CG) molecular dynamics-based approach that can effectively capture the hydrodynamics of complex systems while retaining essential information about the structural properties of the molecular species. An advantageous feature of DPD is that it utilizes soft repulsive interactions between the beads, which are CG representation of groups of atoms or molecules. In this study, we used the DPD simulation technique to study the aggregation characteristics of ABA triblock copolymers in aqueous medium. Pluronic polymers (PEG-PPO-PEG) were modeled as two segments of hydrophilic beads and one segment of hydrophobic beads. Tyrosine-derived PEG5K-b-oligo(desaminotyrosyl tyrosine octyl ester-suberate)-b-PEG5K (PEG5K-oligo(DTO-SA)-PEG5K) block copolymers possess alternate rigid and flexible components along the hydrophobic oligo(DTO-SA) chain, and were modeled as two segments of hydrophilic beads and one segment of hydrophobic, alternate soft and hard beads. The formation, structure, and morphology of the initial aggregation of the polymer molecules in aqueous medium were investigated by following the aggregation dynamics. The dimensions of the aggregates predicted by the computational approach were in good agreement with corresponding results from experiments, for the Pluronic and PEG5K-oligo(DTO-SA)-PEG5K block copolymers. In addition, DPD simulations were utilized to determine the critical aggregation concentration (CAC), which was compared with corresponding results from an experimental approach. For Pluronic polymers F68, F88, F108, and F127, the computational results agreed well with experimental measurements of the CAC measurements. For PEG5K-b-oligo(DTO-SA)-b-PEG5K block polymers, the complexity in polymer structure made it difficult to directly determine their CAC values via the CG scheme. Therefore, we determined CAC values of a series of triblock copolymers with 3-8 DTO-SA units using DPD simulations, and used these results to predict the CAC values of triblock copolymers with higher molecular weights by extrapolation. In parallel, a PEG5K-b-oligo(DTO-SA)-b-PEG5K block copolymer was synthesized, and the CAC value was determined experimentally using the pyrene method. The experimental CAC value agreed well with the CAC value predicted by simulation. These results validate our CG models, and demonstrate an avenue to simulate and predict aggregation characteristics of ABA amphiphilic triblock copolymers with complex structures.

Polymer-xerogel composite materials have been introduced to better optimize local anesthetics release kinetics for the pain management. In a previous study, it was shown that by adjusting various compositional and nano-structural properties of both inorganic xerogels and polymers, zero-order release kinetics over 7 days can be achieved in vitro. In this study, in vitro release properties are confirmed in vivo using a model that tests for actual functionality of the released local anesthetics.

The clinical application of gene silencing is hindered by poor stability and low delivery efficiency of naked oligonucleotides. Here, we present the in vitro and in vivo behaviors of a rationally designed, ternary, self-assembled nanoparticle complex, consisting of an anionic copolymer, cationic DOTAP liposome, and antisense oligonucleotide (AON). The multifunctional copolymers are based on backbone poly(propylacrylic acid) (PPAA), a pH-sensitive hydrophobic polymer, with grafted poly(alkylene oxides) (PAOs) varying in extent of grafting and PAO chemistry. The nanoparticle complexes with PPAA-g-PAO copolymers enhance antisense gene silencing effects in A2780 human ovarian cancer cells. A greater amount of AON is delivered to ovarian tumor xenografts using the ternary copolymer-stabilized delivery system, compared to a binary DOTAP/AON complex, following intraperitoneal injection in mice. Further, intratumoral injection of the nanoparticle complexes containing 1 mol% grafted PAO reduced tumoral bcl-2 expression by up to 60%. The data for complexes across the set of PAO polymers support a strong role for the hydrophilic–lipophilic balance of the graft copolymer in achieving serum stability and cellular uptake. Based upon these results, we anticipate that this novel nanoparticle delivery system can be extended to the delivery of plasmid DNA, siRNA, or aptamers for preclinical and clinical development.

Peptides have enormous potential as therapeutic agents for the treatment of infection, in immunomodulation and for other medical applications, but their hydrolytic degradation in biological fluids is a serious limitation to their in vivo performance. Here we demonstrate the potential utility of polyelectrolyte nanoparticle complexes of novel self-assembling anionic graft copolymers for protecting peptides from degradation in human plasma. The anionic graft copolymers are synthesized by covalently attaching pendent polyetheramine chains to poly(alkylacrylic acid) backbones by carbodiimide coupling. The peptide:copolymer nanocomplexes' particle size, zeta-potential, peptide binding, and controlled release of the peptide are shown to be dependent upon the pendent chain graft density, polymer backbone alkyl groups (propyl vs. methyl), and the nanocomplexes' electrostatic charge ratio. The nanocomplexes can provide substantial protection to the bound peptides from degradation in human plasma for at least 24 h and, in standard microbiological assays are shown to retain some or all of the peptide's antimicrobial activity against a clinically relevant strain of Staphylococcus aureus.

INTRODUCTION:Managing burn injury-associated pain and wounds is a major unresolved clinical problem. Opioids, nonsteroidal antiinflammatory drugs (NSAIDs), antidepressants and anticonvulsants remain the most common forms of analgesic therapy to treat burn patients. However, prolonged treatment with these drugs leads to dose escalation and serious side effects. Additionally, severe burn wounds cause scarring and are susceptible to infection. Recent encouraging findings demonstrate that curcumin, a major bioactive component found in turmeric, is a natural pharmacotherapeutic for controlling both severe burn pain and for improved wound healing.AREAS COVERED:This article covers current pr-clinical and clinical studies on the analgesic and wound healing effects. Particular emphasis has been placed on studies aimed at developing improved curcumin delivery vehicles that increase its bioavailability. Based on the available evidence, a hypothesis is proposed that the dual beneficial effects of curcumin, analgesia and enhanced wound healing are mediated through common anti-inflammatory mechanisms.EXPERT OPINION:Emerging studies have demonstrated that curcumin is a promising investigational drug to treat both pain and wounds. The adequate control of severe burn pain, particularly over the long courses required for healing, as well improvements in burn wound healing are unmet clinical needs.

Biodegradable polymer–ceramic composites offer significant potential advantages in biomedical applications where the properties of either polymers or ceramics alone are insufficient to meet performance requirements. Here we demonstrate the highly tunable mechanical and controlled drug delivery properties accessible with novel biodegradable nanocomposites prepared by non-covalent binding of silica xerogels and co-polymers of tyrosine–poly(ethylene glycol)-derived poly(ether carbonate). The Young’s moduli of the nanocomposites exceed by factors of 5–20 times those of the co-polymers or of composites made with micron scale silica particles. Increasing the fraction of xerogel in the nanocomposites increases the glass transition temperature and the mechanical strength, but decreases the equilibrium water content, which are all indicative of strong non-covalent interfacial interactions between the co-polymers and the silica nanoparticles. Sustained, tunable controlled release of both hydrophilic and hydrophobic therapeutic agents from the nanocomposites is demonstrated with two clinically significant drugs, rifampicin and bupivacaine. Bupivacaine exhibits an initial small burst release followed by slow release over the 7day test period. Rifampicin release fits the diffusion-controlled Higuchi model and the amount released exceeds the dosage required for treatment of clinically challenging infections. These nanocomposites are thus attractive biomaterials for applications such as wound dressings, tissue engineering substrates and stents.

The advancement of gene-based therapeutics to the clinic is limited by the ability to deliver physiologically relevant doses of nucleic acids to target tissues safely and effectively. Over the last couple of decades, researchers have successfully employed polymer and lipid based nanoassemblies to deliver nucleic acids for the treatment of a variety of diseases. Results of phase I/II clinical studies to evaluate the efficacy and biosafety of these gene delivery vehicles have been encouraging, which has promoted the design of more efficient and biocompatible systems. Research has focused on designing carriers to achieve biocompatibility, stability in the circulatory system, biodistribution to target the disease site, and intracellular delivery, all of which enhance the resulting therapeutic effect. The family of poly(alkylene oxide) (PAO) polymers includes random, block, and branched structures, among which the ABA type triblocks copolymers of ethylene oxide (EO) and propylene oxide (PO) (commercially known as Pluronic) have received the greatest consideration. In this Account, we highlight examples of polycation-PAO conjugates, liposome-PAO formulations, and PAO micelles for nucleic acid delivery. Among the various polymer design considerations, which include molecular weight of polymer, molecular weight of blocks, and length of blocks, the overall hydrophobic-lipophilic balance (HLB) is a critical parameter in defining the behavior of the polymer conjugates for gene delivery. We discuss the effects of varying this parameter in the context of improving gene delivery processes, such as serum stability and association with cell membranes. Other innovative macromolecular modifications discussed in this category include our work to enhance the serum stability and efficiency of lipoplexes using PAO graft copolymers, the development of a PAO gel-based carrier for sustained and stimuli responsive delivery, and the development of biodegradable PAO-based amphiphilic block copolymers.

Heterotopic ossification (HO) associated with traumatic neurological or musculoskeletal injuries remains a major clinical challenge. One approach to understanding better and potentially treating this condition is to silence one or more genes believed to be responsible for osteogenesis by small interfering RNA (siRNA) post-injury. Improved methods of delivering siRNA to myoprogenitor cells as well as relevant cell culture models of HO are needed to advance this approach. We utilize a model of HO featuring C2C12 myoprogenitor cells stimulated to the osteogenic phenotype by addition of BMP-2. For siRNA delivery, we utilize a nanocomposite consisting of DOTAP-based cationic liposomes coated with a graft copolymer of poly(propylacrylic acid) grafted with polyetheramine (Jeffamine), as this system has been shown previously to deliver antisense oligonucleotides safely into cells and out of endosomes for gene silencing in vitro and in vivo. Delivery of siRNA targeting Runx2, a transcription factor downstream of BMP-2, to stimulated C2C12 cells produced greater than 60% down-regulation of the Runx2 gene. This level of gene silencing was sufficient to inhibit alkaline phosphatase activity over the course of several days and calcium phosphate deposition over the course of 2 weeks. These results show the utility of the BMP-2/C2C12 model for capturing the cellular cell-fate decision in HO. Further, they suggest DOTAP/PPAA-g-Jeffamine as a promising delivery system for siRNA-based therapy for HO.