Evaluation ofin vitro release andin vivo efficacy of mPEG-PLA-haloperidol conjugate micelle-like structures

Enhanced design and formulation of nanoparticles for anti-biofilm drug delivery

Biofilms are surface-bound, structured microbial communities underpinning persistent bacterial infections. Biofilms often create acidic pH microenvironments, providing opportunities to leverage responsive drug delivery systems to improve antibacterial efficacy. Here, the antibacterial efficacy of novel formulations containing pH-responsive polymer nanoparticle carriers (NPCs) and farnesol, a hydrophobic antibacterial drug, were investigated. Multiple farnesol-loaded NPCs, which varied in overall molecular weight and corona-to-core molecular weight ratios (CCRs), were tested using standard and saturated drug loading conditions. NPCs loaded at saturated conditions exhibited ∼300% greater drug loading capacity over standard conditions. Furthermore, saturated loading conditions sustained zero-ordered drug release over 48 hours, which was 3-fold longer than using standard farnesol loading. Anti-biofilm activity of saturated NPC loading was markedly amplified using Streptococcus mutans as a biofilm-forming model organism. Specifically, reductions of ∼2-4 log colony forming unit (CFU) were obtained using microplate and saliva-coated hydroxyapatite biofilm assays. Mechanistically, the new formulation reduced total biomass by disrupting insoluble glucan formation and increased NPC-cell membrane localization. Finally, thonzonium bromide, a highly potent, FDA-approved antibacterial drug with similar alkyl chain structure to farnesol, was also loaded into NPCs and used to treat S. mutans biofilms. Similar to farnesol-loaded NPCs, thonzonium bromide-loaded NPCs increased drug loading capacity ≥2.5-fold, demonstrated nearly zero-order release kinetics over 96 hours, and reduced biofilm cell viability by ∼6 log CFU. This work provides foundational insights that may lead to clinical translation of novel topical biofilm-targeting therapies, such as those for oral diseases.

Building the design, translation and development principles of polymeric nanomedicines using the case of clinically advanced poly(lactide(glycolide))-poly(ethylene glycol) nanotechnology as a model: An industrial viewpoint

The design of the first polymeric nanoparticles could be traced back to the 1970s, and has thereafter received considerable attention, as evidenced by the significant increase of the number of articles and patents in this area. This review article is an attempt to take advantage of the existing literature on the clinically tested and commercialized biodegradable PLA(G)A-PEG nanotechnology as a model to propose quality building and outline translation and development principles for polymeric nano-medicines. We built such an approach from various building blocks including material design, nano-assembly - i.e. physicochemistry of drug/nano-object association in the pharmaceutical process, and release in relevant biological environment - characterization and identification of the quality attributes related to the biopharmaceutical properties. More specifically, as envisaged in a translational approach, the reported data on PLA(G)A-PEG nanotechnology have been structured into packages to evidence the links between the structure, physicochemical properties, and the in vitro and in vivo performances of the nanoparticles. The integration of these bodies of knowledge to build the CMC (Chemistry Manufacturing and Controls) quality management strategy and finally support the translation to proof of concept in human, and anticipation of the industrialization takes into account the specific requirements and biopharmaceutical features attached to the administration route. From this approach, some gaps are identified for the industrial development of such nanotechnology-based products, and the expected improvements are discussed. The viewpoint provided in this article is expected to shed light on design, translation and pharmaceutical development to realize their full potential for future clinical applications.

A novel PEG–haloperidol conjugate with a non-degradable linker shows the feasibility of using polymer–drug conjugates in a non-prodrug fashion

A PEG–haloperidol conjugate was synthesised, which retains binding to the dopamine D₂receptor, showing the possibility of using polymer-drug conjugates as drugsper se' rather than as prodrugs.

Which polymer is more suitable for etoposide: A comparison between two kinds of drug loaded polymeric micelles in vitro and in vivo?

In this paper, we systemly compared the two kinds of VP16 (etoposide) loaded polymers micelles, monomethyl poly (ethylene glycol)-poly (lactic acid) (MPEG-PDLLA) and monomethyl poly (ethylene glycol)-poly (ϵ-caprolactone) (MPEG-PCL) in vitro and in vivo. Molecular modeling study was used as a novel means to compare the two formulations. In vitro, the micelle samples were fully characterized by TEM, XRD, drug loading (DL), Encapsulation efficiency (EE), stability and MTT. The stability study revealed that MPEG-PDLLA-VP16 had the significant advantage of 100% drug retention within 48 h compared to MPEG-PCL-VP16 with 40%, conform to the computer simulation model results. Cellular uptake figured that MPEG-PDLLA-VP16 had a 7 times larger uptake rate in the H460 cell line. In vivo, pharmacodynamics results showed MPEG-PDLLA-VP16 perform no significant difference with VP16 clinical formulations (10, 20mg/kg). However, MPEG-PCL-VP16 had no difference between different dosages on anticancer activities. Plasma pharmacokinetics results showed that the two micelle formulations prolong the half-life of VP16 twice than that of VP16 clinical formulations. In conclusion, micelle were better choice for cancer treatment on reducing drug toxic. In this study, the results also indicated that MPEG-PDLLA was more suitable for VP16 than MPEG-PCL as a more promising formulation for clinical cancer treatment.

A Review of Intra- and Extracellular Antigen Delivery Systems for Virus Vaccines of Finfish

Vaccine efficacy in aquaculture has for a long time depended on evaluating relative percent survival and antibody responses after vaccination. However, current advances in vaccine immunology show that the route in which antigens are delivered into cells is deterministic of the type of adaptive immune response evoked by vaccination. Antigens delivered by the intracellular route induce MHC-I restricted CD8+ responses while antigens presented through the extracellular route activate MHC-II restricted CD4+ responses implying that the route of antigen delivery is a conduit to induction of B- or T-cell immune responses. In finfish, different antigen delivery systems have been explored that include live, DNA, inactivated whole virus, fusion protein, virus-like particles, and subunit vaccines although mechanisms linking these delivery systems to protective immunity have not been studied in detail. Hence, in this review we provide a synopsis of different strategies used to administer viral antigens via the intra- or extracellular compartments. Further, we highlight the differences in immune responses induced by antigens processed by the endogenous route compared to exogenously processed antigens. Overall, we anticipate that the synopsis put together in this review will shed insights into limitations and successes of the current vaccination strategies used in finfish vaccinology.

Analysis of immediate stress mechanisms upon injection of polymeric micelles and related colloidal drug carriers: implications on drug targeting

Polymeric micelles are ideal carriers for solubilization and targeting applications using hydrophobic drugs. Stability of colloidal aggregates upon injection into the bloodstream is mandatory to maintain the drugs' targeting potential and to influence pharmacokinetics. In this review we analyzed and discussed the most relevant stress mechanisms that polymeric micelles and related colloidal carriers encounter upon injection, including (1) dilution, (2) interactions with blood components, and (3) immunological responses of the body. In detail we analyzed the opsonin-dysopsonin hypothesis that points at a connection between a particles' protein-corona and its tissue accumulation by the enhanced permeability and retention (EPR) effect. In the established theory, size is seen as a necessary condition to reach nanoparticle accumulation in disease modified tissue. There is, however, mounting evidence of other sufficient conditions (e.g., particle charge, receptor recognition of proteins adsorbed onto particle surfaces) triggering nanoparticle extravasation by active mechanisms. In conclusion, the analyzed stress mechanisms are directly responsible for in vivo success or failure of the site-specific delivery with colloidal carrier systems.

Materials for pharmaceutical dosage forms: molecular pharmaceutics and controlled release drug delivery aspects

Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development.