Peptides and peptide-conjugates, comprising natural and synthetic building blocks, are an increasingly popular class of biomaterials. Self-assembled nanostructures based on peptides and peptide-conjugates offer advantages such as precise selectivity and multifunctionality that can address challenges and limitations in the clinic. In this review article, we discuss recent developments in the design and self-assembly of various nanomaterials based on peptides and peptide-conjugates for medical applications, and categorize them into two themes based on the driving forces of molecular self-assembly. First, we present the self-assembled nanostructures driven by the supramolecular interactions between the peptides, with or without the presence of conjugates. The studies where nanoassembly is driven by the interactions between the conjugates of peptide-conjugates are then presented. Particular emphasis is given to in vivo studies focusing on therapeutics, diagnostics, immune modulation and regenerative medicine, and challenges and future perspective are presented.

Data on 1898 menstrual cycles, for 241 married women, were analysed by means of a quantal regression programme. The locations of the day of ovulation was determined by the basal body temperature method. Estimates were obtained of the risk of conception from an act of coitus on each day, as measured from the day of ovulation. The relationship between fecundability and coital frequency was also examined.

Abstract. Delivery system design and adjuvant development are crucially important areas of research for improving vaccines. Peptide amphiphile micelles are a class of biomaterials that have the unique potential to function as both vaccine delivery vehicles and self-adjuvants. In this study, peptide amphiphiles comprised of a group A streptococcus B cell antigen (J8) and a dialkyl hydrophobic moiety (diC 16 ) were synthesized and organized into self-assembled micelles, driven by hydrophobic interactions among the alkyl tails. J8-diC 16 formed cylindrical micelles with highly α-helical peptide presented on their surfaces. Both the micelle length and secondary structure were shown to be enhanced by annealing. When injected into mice, J8-diC 16 micelles induced a strong IgG1 antibody response that was comparable to soluble J8 peptide supplemented with two classical adjuvants. It was discovered that micelle adjuvanticity requires the antigen be a part of the micelle since separation of J8 and the micelle was insufficient to induce an immune response. Additionally, the diC 16 tail appears to be non-immunogenic since it does not stimulate a pathogen recognition receptor whose agonist (Pam 3 Cys) possesses a very similar chemical structure. The research presented in this paper demonstrates the promise peptide amphiphile micelles have in improving the field of vaccine engineering.

Summary Background The development of neutralizing antibodies, referred to as inhibitors, against factor VIII (FVIII) is a major complication associated with FVIII infusion therapy for the treatment of hemophilia A (HA). Previous studies have shown that a subset of HA patients and a low percentage of healthy individuals harbor non-neutralizing anti-FVIII antibodies that do not elicit the clinical manifestations associated with inhibitor development. Objective Assess HA patients' anti-FVIII antibody profiles as potential predictors of clinical outcomes. Methods A fluorescence immunoassay (FLI) was used to detect anti-FVIII antibodies in 491 samples from 371 HA patients. Results Assessments of antibody profiles showed that the presence of anti-FVIII IgG1, IgG2, or IgG4 correlated qualitatively and quantitatively with the presence of a FVIII inhibitor as reported by the Nijmegen-Bethesda assay (NBA). Forty-eight patients with a negative inhibitor history contributed serial samples to the study, including seven patients who had negative NBA titers initially and later converted to NBA-positive. The FLI detected anti-FVIII IgG1 in five of those seven patients prior to their conversion to NBA-positive. Five of 15 serial-sample patients who had a negative inhibitor history and a positive anti-FVIII IgG1 later developed an inhibitor, compared to 2 of 33 patients with a negative inhibitor history without anti-FVIII IgG1. Conclusions These data provide a rationale for future studies designed both to monitor the dynamics of anti-FVIII antibody profiles in HA patients as a potential predictor of future inhibitor development and to assess the value of the anti-FVIII FLI as a supplement to traditional inhibitor testing.

Neutralizing antibodies (inhibitors) to replacement Factor-VIII impair the effective management of hemophilia-A1. Individuals with hemophilia-A due to major F8 gene disruptions lack antigenically cross-reactive material in their plasma (CRM-negative) and prevalence of inhibitors is >60%. Conversely, subjects with missense mutations are CRM-positive and the prevalence of inhibitors is <10%2. Individuals with the intron-22-inversion (~50% of individuals with severe hemophilia-A) should be in the former group based on the genetic defect. Although these individuals are CRM-negative, only 20% of them develop inhibitors3. Here we demonstrate the presence of comparable levels of F8 mRNA and intracellular Factor-VIII protein in B-lymphoblastoid cells and liver biopsies from healthy controls and subjects with the intron-22-inversion. These results support the hypothesis that most individuals with the intron-22-inversion are tolerized to Factor-VIII and thus do not develop inhibitors. Furthermore we developed a pharmacogenetic algorithm that permits the stratification of inhibitor risk for sub-populations by predicting immunogenicity using, as input, the number of putative T-cell epitopes in the infused FVIII and the competence of MHC-Class-II molecules to present such epitopes. The algorithm exhibited significant accuracy in predicting inhibitors in 25 unrelated individuals with the intron-22-inversion (AUC = 0.890; P = 0.001).

Radiolabeled (14C) 2-[4-(3-chloro-5-trifluoromethyl-2-pyridinyloxy)phenoxy] propionic acid (Compound C); its methyl-,n-butyl-, and ethoxyethyl-esters; and fluazifop-butyl {(±)-butyl 2-[4-[(5-(trifluoromethyl)-2-pyridinyl)oxy] phenoxy] propionate} were applied to the primary shoots of young rhizomatous quackgrass [Agropyron repens(L.) Beauv. # AGRRE]. Plants were sampled from 0.5 to 24 days after treatment (DAT) and analyzed for radiochemical. All treatments caused phytotoxic symptoms in primary shoots, rhizomes, and tillers and significantly reduced growth of primary shoots and rhizomes. Treatment with compound C or its methyl and butyl esters eliminated regrowth from all rhizomes excised from treated plants. The ethoxyethyl-ester and fluazifop-butyl controlled regrowth from rhizomes from 50% of the plants and substantially reduced shoot regrowth from the remainder. Rhizomes that did produce shoots contained significantly less radiochemical than those from which no regrowth occurred. At 24 DAT, a maximum of only 1% of each radiochemical applied was translocated to the first tiller and rhizomes and had been sufficient to cause marked phytotoxic symptoms. Soon after application (1 DAT), the major metabolites in the treated leaves and remainder of the plant for all compounds were the free acid and substantial amounts of polar conjugates that were hydrolyzable to the free acids. Radiochromatography of extracts from rhizomes and first tillers from all treatments gave similar chemical profiles, with the free acids and their conjugates as the predominant components present. These results provide evidence that esters of the pyridinyloxyphenoxypropionic acids are rapidly hydrolyzed after absorption by quackgrass; the free acids are then translocated and are the active form of these herbicides.

Inducing a strong and specific immune response is the hallmark of a successful vaccine. Nanoparticles have emerged as promising vaccine delivery devices to discover and elicit immune responses. Fine-tuning a nanoparticle vaccine to create an immune response with specific antibody and other cellular responses is influenced by many factors such as shape, size, and composition. Peptide amphiphile micelles are a unique biomaterials platform that can function as a modular vaccine delivery system, enabling control over many of these important factors and delivering payloads more efficiently to draining lymph nodes. In this study, the modular properties of peptide amphiphile micelles are utilized to improve an immune response against a Group A Streptococcus B cell antigen (J8). The hydrophobic/hydrophilic interface of peptide amphiphile micelles enabled the precise entrapment of amphiphilic adjuvants which were found to not alter micelle formation or shape. These heterogeneous micelles significantly enhanced murine antibody responses when compared to animals vaccinated with nonadjuvanted micelles or soluble J8 peptide supplemented with a classical adjuvant. The heterogeneous micelle induced antibodies also showed cross-reactivity with wild-type Group A Streptococcus providing evidence that micelle-induced immune responses are capable of identifying their intended pathogenic targets.

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