In Vitro and In Vivo Hydrolytic Degradation Behaviors of a Drug-Delivery System Based on the Blend of PEG and PLA Copolymers.

This paper presents the in vitro and in vivo degradation of BEPO, a marketed in situ forming depot technology used for the formulation of long-acting injectables. BEPO is composed of a solution of a blend of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) triblock and diblock in an organic solvent, where a therapeutic agent may be dissolved or suspended. Upon contact with an aqueous environment, the solvent diffuses and the polymers precipitate, entrapping the drug and forming a reservoir. Two representative BEPO compositions were subjected to a 3-month degradation study in vitro by immersion in phosphate-buffered saline at 37 °C and in vivo after subcutaneous injection in minipig. The material erosion rate, as a surrogate of the bioresorption, determined via the depot weight loss, changed substantially, depending on the composition and content of polymers within the test item. The swelling properties and internal morphology of depots were shown to be highly dependent on the solvent exchange rate during the precipitation step. Thermal analyses displayed an increase of the depot glass transition temperature over the degradation process, with no crystallinity observed at any stage. The chemical composition of degraded depots was determined by 1H NMR and gel permeation chromatography and demonstrated an enrichment in homopolymers, i.e., free PLA and (m)PEG, to the detriment of (m)PEG-PLA copolymers in both formulations. It was observed that the relative ratio of the degradants within the depot is driven by the initial polymer composition. Interestingly, in vitro and in vivo results showed very good qualitative consistency. Taken together, the outcomes from this study demonstrate that the different hydrolytic degradation behaviors of the BEPO compositions can be tuned by adjusting the polymer composition of the formulation.

A two-tiered system for selective receptor and transporter protein degradation.

Diverse physiology relies on receptor and transporter protein down-regulation and degradation mediated by ESCRTs. Loss-of-function mutations in human ESCRT genes linked to cancers and neurological disorders are thought to block this process. However, when homologous mutations are introduced into model organisms, cells thrive and degradation persists, suggesting other mechanisms compensate. To better understand this secondary process, we studied degradation of transporter (Mup1) or receptor (Ste3) proteins when ESCRT genes (VPS27, VPS36) are deleted in Saccharomyces cerevisiae using live-cell imaging and organelle biochemistry. We find that endocytosis remains intact, but internalized proteins aberrantly accumulate on vacuolar lysosome membranes within cells. Here they are sorted for degradation by the intralumenal fragment (ILF) pathway, constitutively or when triggered by substrates, misfolding or TOR activation in vivo and in vitro. Thus, the ILF pathway functions as fail-safe layer of defense when ESCRTs disregard their clients, representing a two-tiered system that ensures degradation of surface polytopic proteins.

Long-acting injectable formulation technologies: challenges and opportunities for the delivery of fragile molecules.

INTRODUCTION: The development of long-acting injectables (LAIs) for protein and peptide therapeutics has been a key challenge over the last 20 years. If these molecules offer advantages due to their high specificity and selectivity, their controlled release may confer several additional benefits in terms of extended half-life, local delivery, and patient compliance. AREA COVERED: This manuscript aims to give an overview of peptide and protein-based LAIs from an industrial perspective, describing both approved and promising technologies (with exceptions of protein engineering strategies and devices), their advantages and potential improvements to aid their access to the market. EXPERT OPINION: Many LAIs have been developed for peptides, with formulations on the market for several decades. On the contrary, LAIs for proteins are still far from the market and issues related to manufacturing and sterilization of these products still need to be overcome. In situ forming depots (ISFDs), whose simple manufacturing conditions and easy administration procedures (without reconstitution) are strong advantages, appear as one of the most promising technologies for the delivery of these molecules. In this regard, the approval of ELIGARD® in the early 2000's (which still requires a complex reconstitution process), paved the way for the development of second-generation, ready-to-use ISFD technologies like BEPO® and FluidCrystal®.

In Vitro Reconstitution of the dTDP-l-Daunosamine Biosynthetic Pathway Provides Insights into Anthracycline Glycosylation.

Many small molecule natural products are decorated with sugar moieties that are essential for their biological activity. A considerable number of natural product glycosides and their derivatives are clinically important therapeutics. Anthracyclines like daunorubicin and doxorubicin are examples of valuable glycosylated natural products used in medicine as potent anticancer agents. The sugar moiety, l-daunosamine (a highly modified deoxyhexose), plays a key role in the bioactivity of these molecules as evidenced by semisynthetic anthracycline derivatives such as epirubicin, wherein alteration in the configuration of a single stereocenter of the sugar unit generates a chemotherapeutic drug with lower cardiotoxicity. The nucleotide activated sugar donor that provides the l-daunosamine group for attachment to the natural product scaffold in the biosynthesis of these anthracyclines is dTDP-l-daunosamine. In an in vitro system, we have reconstituted the enzymes in the daunorubicin/doxorubicin pathway involved in the biosynthesis of dTDP-l-daunosamine. Through the study of the enzymatic steps in this reconstituted pathway, we have gained several insights into the assembly of this precursor including the identification of a major bottleneck and competing reactions. We carried out kinetic analysis of the aminotransferase that catalyzes a limiting step of the pathway. Our in vitro reconstituted pathway also provided a platform to test the combinatorial enzymatic synthesis of other dTDP-activated deoxyhexoses as potential tools for "glycodiversification" of natural products. To this end, we replaced the stereospecific ketoreductase that acts in the last step of dTDP-l-daunosamine biosynthesis with an enzyme from a heterologous pathway with opposite stereospecificity and found that it is active in the in vitro pathway, demonstrating the potential for the enzymatic synthesis of nucleotide-activated sugars with regio- and stereospecific tailoring.

Evaluation of Loco-Regional Skin Toxicity Induced by an In Situ Forming Depot after a Single Subcutaneous Injection at Different Volumes and Flow Rates in Göttingen Minipigs.

The present study aims to investigate the loco-regional tolerability and injection parameters (i.e., flow rate and administration volume) of an in situ forming depot (ISFD) in Göttingen minipigs, to secure both the therapeutic procedure and compliance in chronic medical prescriptions. The ISFD BEPO® technology (MedinCell S.A.) is investigated over 10 days, after a single subcutaneous injection of test item based on a DMSO solution of diblock and triblock polyethylene glycol-polylactic acid copolymers. Injection sites are systematically observed for macroscopic loco-regional skin reactions as well as ultrasound scanning, enabling longitudinal in vivo imaging of the depot. Observations are complemented by histopathological examinations at 72 h and 240 h post-injection. Overall, no treatment-emergent adverse effects are macroscopically or microscopically observed at the subcutaneous injection sites, for the tested injection flow rates of 1 and 8 mL/min and volumes of 0.2 and 1 mL. The histopathology examination confirms an expected foreign body reaction, with an intensity depending on the injected volume. The depot morphology is similar irrespective of the administration flow rates. These results indicate that the ISFD BEPO® technology can be considered safe when administered subcutaneously in Göttingen minipigs, a human-relevant animal model for subcutaneous administrations, in the tested ranges.

Impact of octreotide counterion nature on the long-term stability and release kinetics from an in situ forming depot technology.

The generation of acylated impurities has represented an important hurdle in the development of long acting injectables for therapeutic peptides using biocompatible polymers with a polyester moiety. We investigated here an in situ forming depot (ISFD) technology that uses polyethylene glycol - polyester copolymers and a solvent exchange mechanism to promote depot formation. This technology has shown promise in formulating small molecules as well as therapeutic proteins. In the present work, using the well-known somatostatin analog octreotide acetate (OctAc) as a model molecule, we evaluated this delivery platform to release therapeutic peptides. Peptide acylation was found to be pronounced in the formulation, while it was very limited once the depot was formed and during the release process. The octreotide acylation pattern was fully characterized by LC-MS/MS. Moreover, it was demonstrated that exchanging the acetate anion with more hydrophobic counterions like pamoate or lauryl sulfate allowed to greatly improve the peptide stability profile, as well as the formulation release performance. Finally, the in vivo evaluation through pharmacokinetics studies in rat of these new octreotide salts in ISFD formulations showed that octreotide was quantifiable up to four weeks post-administration with a high bioavailability and an acceptable initial burst.

Challenges and opportunities in the delivery of cancer therapeutics: update on recent progress.

Global cancer prevalence has continuously increased in the last decades despite substantial progress achieved for patient care. Cancer is no longer recognized as a singular disease but as a plurality of different ones, leading to the important choice of the drug administration route and promoting the development of novel drug-delivery systems (DDS). Due to their structural diversity, therapeutic cancer drugs present specific challenges in physicochemical properties that can adversely affect their efficacy and toxicity profile. These challenges are addressed by innovative DDS to improve bioavailability, pharmacokinetics and biodistribution profiles. Here, we define the drug delivery challenges related to oral, intravenous, subcutaneous or alternative routes of administration, and review innovative DDS, marketed or in development, that answer those challenges.

BEPO®: Bioresorbable diblock mPEG-PDLLA and triblock PDLLA-PEG-PDLLA based in situ forming depots with flexible drug delivery kinetics modulation.

This article presents BEPO®, an in situ forming depot (ISFD) technology mediated by a solvent-exchange mechanism. The matrix of the in situ formed drug delivery depot is composed of the combination of a diblock (DB) and a triblock (TB) polyethylene glycol-polyester copolymer. This combination offers a broad capability to tune the release of a wide variety of drugs to the desired pharmacokinetics. The work described in the present article demonstrates that the delivery rate and profile can be adjusted by changing the composition of either TB or DB or the relative ratio between them, among other parameters. It has been shown that the polymeric composition of the formulation has a substantial impact on the solvent exchange rate between the organic solvent and the surrounding aqueous medium which subsequently determines the internal structure of the resulting depot and the delivery of the therapeutic cargo. This has been demonstrated studying the in vitro release of two model molecules: bupivacaine and ivermectin. Formulations releasing these drugs have been administered to animal models to show the possibility of delivering therapeutics from weeks to months by using BEPO® technology.

Organic Nanoscrolls from Electrostatic Interactions between Peptides and Lipids: Assembly Steps and Structure.

An important aspect of cells is their shape flexibility that gives them motion but also a high adaptation versatility to their environment. This shape versatility is mediated by different types of protein-membrane interactions among which electrostatic plays an important role. In the present work we examined the interaction between a small dicationic peptide, that possesses self-assembly properties, and lipid model membranes. The peptide, lanreotide, spontaneously forms nanotubes in water that have a strictly uniform diameter. In the current work, we show that the interaction between the cationic peptide and negatively charged bilayers of lipids induces the formation of myelin sheath-like structures that we call nanoscrolls. By deciphering the different steps of formation and the molecular structure of the self-assembly, we show how electrostatics modify the spontaneous peptide and lipid way of packing.

Scapular Notching in Reverse Total Shoulder Arthroplasty.

Scapular notching is a common radiographic finding occurring after reverse total shoulder arthroplasty, and it refers to an erosive lesion of the inferior scapular neck because of the impingement of the humeral implant during adduction. The clinical importance of notching is unclear, and the optimal treatment of severe notching is unknown. The incidence and severity of scapular notching is related to prosthetic design and surgical technique. Implant design factors include size, shape, and position of the glenosphere, inclination of the humeral neck-shaft angle, implant offset, and native scapular anatomy. Scapular notching may lead to deterioration of functional outcomes and glenoid implant loosening and failure. Lateral offset, inferior glenosphere overhang, and careful consideration of the presurgical glenoid morphology may help prevent scapular notching. Currently, there is limited evidence to direct the management of scapular notching, and further research is needed to elucidate optimal prevention and treatment strategies.

A Genome-Wide Screen Identifies Genes in Rhizosphere-Associated Pseudomonas Required to Evade Plant Defenses.

Pseudomonas fluorescens and related plant root ("rhizosphere")-associated species contribute to plant health by modulating defenses and facilitating nutrient uptake. To identify bacterial fitness determinants in the rhizosphere of the model plant Arabidopsis thaliana, we performed a high-throughput transposon sequencing (Tn-Seq) screen using the biocontrol and growth-promoting strain Pseudomonas sp. WCS365. The screen, which was performed in parallel on wild-type and immunocompromised Arabidopsis plants, identified 231 genes that increased fitness in the rhizosphere of wild-type plants. A subset of these genes decreased fitness in the rhizosphere of immunocompromised plants. We hypothesized that these genes might be involved in avoiding plant defenses and verified 7 Pseudomonas sp. WCS365 candidate genes by generating clean deletions. We found that two of these deletion mutants, ΔmorA (encoding a putative diguanylate cyclase/phosphodiesterase) and ΔspuC (encoding a putrescine aminotransferase), formed enhanced biofilms and inhibited plant growth. We found that mutants ΔspuC and ΔmorA induced pattern-triggered immunity (PTI) as measured by induction of an Arabidopsis PTI reporter and FLS2/BAK1-dependent inhibition of plant growth. We show that MorA acts as a phosphodiesterase to inhibit biofilm formation, suggesting a possible role in biofilm dispersal. We found that both putrescine and its precursor arginine promote biofilm formation that is enhanced in the ΔspuC mutant, which cannot break down putrescine, suggesting that putrescine might serve as a signaling molecule in the rhizosphere. Collectively, this work identified novel bacterial factors required to evade plant defenses in the rhizosphere.IMPORTANCE While rhizosphere bacteria hold the potential to improve plant health and fitness, little is known about the bacterial genes required to evade host immunity. Using a model system consisting of Arabidopsis and a beneficial Pseudomonas sp. isolate, we identified bacterial genes required for both rhizosphere fitness and for evading host immune responses. This work advances our understanding of how evasion of host defenses contributes to survival in the rhizosphere.

Readability of advance directive documentation in Canada: a cross-sectional study.

BACKGROUND: In the Canadian context, health literacy has been shown to depend on place of birth, education level, socioeconomic status, language spoken and geographic location. This study seeks to determine whether currently available advance directive documentation in Canada is written in accordance with the average reading level of the population and to assess whether recommendations for health literacy are currently being met. METHODS: A cross-sectional study design was used. Patient-oriented English-language advance directive documents (brochures and/or forms) were obtained from the health agency websites of all Canadian provinces and territories and analyzed for readability using the Flesch-Kincaid Grade Level and Flesch Readability Ease scales. RESULTS: Advance directives in Canada are distinct from one another and surpass the recommended reading level by 4.5 ± 1.4 grade levels on average (95% confidence interval 8.7-10.3) with the hardest-to-read documents existing in Ontario, Quebec and Alberta. INTERPRETATION: These results demonstrate that the provincial and territorial governments issuing advance directive documentation have fallen short of their fiduciary responsibility to provide documents that facilitate health literacy. Addressing this shortcoming can result in increased patient engagement in advance directive completion while promoting patient autonomy.

Challenges in oral peptide delivery: lessons learnt from the clinic and future prospects.

Therapeutic peptides have become very successful drugs due to their specificity, potency and low toxicity, but they show challenges for their delivery, due to their short half-life and rapid plasma clearance. For these reasons, peptides are usually administered using injectable sustained-release formulations. Oral peptide route is highly compelling from a patient and commercial point of view. However, poor peptide stability and low permeability across the intestinal epithelium still make it very challenging to effectively deliver peptides by the oral route. In this paper, biopharmaceutical and formulation features of oral peptides, as well as key clinical outcomes, are reviewed and discussed in the perspective of designing next generation of oral peptide formulations for a true paradigm shift.

Lanreotide Depot: An Antineoplastic Treatment of Carcinoid or Neuroendocrine Tumors.

PURPOSE: Peptide drugs for antineoplastic therapies usually have low oral bioavailability and short in vivo half-lives, requiring less preferred delivery methods. Lanreotide depot is a sustained-release somatostatin analog (SSA) formulation produced via an innovative peptide self-assembly method. Lanreotide is approved in the USA and Europe to improve progression-free survival (PFS) in patients with unresectable gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and also approved in Europe for symptom control in carcinoid syndrome associated with GEP-NETs. This review discusses how the distinct molecule and formulation of lanreotide depot provide advantages to patients and health care providers, as well as the most recent clinical evidence demonstrating the safety and efficacy of lanreotide depot in inhibiting tumor growth and controlling hormonal symptoms in GEP-NETs. METHODOLOGY AND RESULTS: The lanreotide depot formulation confers a remarkable pharmacokinetic profile with no excipients, comprised only of lanreotide acetate and water. Of note, lanreotide depot constitutes an example for peptide self-assembly based formulations, providing insights that could help future development of sustained-release formulations of other antineoplastic peptides. Most patients with GEP-NETs will present with inoperable or incurable disease; thus, medical management for symptoms and tumor control plays a crucial role. Recent long-term clinical studies have demonstrated that lanreotide depot is well tolerated, prolongs PFS in GEP-NET patients, and significantly reduces symptoms related to carcinoid syndrome. CONCLUSIONS: The unique depot formulation and delivery method of lanreotide confer advantages in the treatment of metastatic GEP-NETs, contributing to improvements in NET-related symptoms and PFS without reducing quality of life in this patient population.

Unlocking Index Animalium: From paper slips to bytes and bits.

In 1996 Smithsonian Libraries (SIL) embarked on the digitization of its collections. By 1999, a full-scale digitization center was in place and rare volumes from the natural history collections, often of high illustrative value, were the focus for the first years of the program. The resulting beautiful books made available for online display were successful to a certain extent, but it soon became clear that the data locked within the texts needed to be converted to more usable and re-purposable form via digitization methods that went beyond simple page imaging and included text conversion elements. Library staff met with researchers from the taxonomic community to understand their path to the literature and identified tools (indexes and bibliographies) used to connect to the library holdings. The traditional library metadata describing the titles, which made them easily retrievable from the shelves of libraries, was not meeting the needs of the researcher looking for more detailed and granular data within the texts. The result was to identify proper print tools that could potential assist researchers in digital form. This paper outlines the project undertaken to convert Charles Davies Sherborn's Index Animalium into a tool to connect researchers to the library holdings: from a print index to a database to eventually a dataset. Sherborn's microcitation of a species name and his bibliographies help bridge the gap between taxonomist and literature holdings of libraries. In 2004, SIL received funding from the Smithsonian's Atherton Seidell Endowment to create an online version of Sherborn's Index Animalium. The initial project was to digitize the page images and re-key the data into a simple data structure. As the project evolved, a more complex database was developed which enabled quality field searching to retrieve species names and to search the bibliography. Problems with inconsistent abbreviations and styling of his bibliographies made the parsing of the data difficult. Coinciding with the development of the Biodiversity Heritage Library (BHL) in 2005, it became obvious there was a need to integrate the database converted Index Animalium, BHL's scanned taxonomic literature, and taxonomic intelligence (the algorithmic identification of binomial, Latinate name-strings). The challenges of working with legacy taxonomic citation, computer matching algorithms, and making connections have brought us to today's goal of making Sherborn available and linked to other datasets. Partnering with others to allow machine-to-machine communications the data is being examined for possible transformation into RDF markup and meeting the standards of Linked Open Data. SIL staff have partnered with Thomson Reuters and the Global Names Initiative to further enhance the Index Animalium data set. Thomson Reuters' staff is now working on integrating the species microcitation and species name in the ION: Index to Organism Names project; Richard Pyle (The Bishop Museum) is also working on further parsing of the text. The Index Animalium collaborative project's ultimate goal is to successful have researchers go seamlessly from the species name in either ION or the scanned pages of Index Animalium to the digitized original description in BHL - connecting taxonomic researchers to original authored species descriptions with just a click.

Evaluation of Three Sensor Types for Particle Motion Measurement.

All fish sense acoustic particle motion; some species also sense pressure. Concern over the effects of anthropogenic sounds is increasing the need to monitor acoustic particle motion. Particle motion can be measured directly using vector sensors or calculated from pressure gradients. This article compares three devices that measure particle motion: a three-axis accelerometer, a three-axis velocity sensor, and two 4-element hydrophone arrays. A series of sounds (constant-wave tones, white noise, and Ricker wavelets) were played from a fixed-position projector. The particle motion of sounds from imploding light bulbs was also measured.

Impact of Prostate Cancer Treatment on the Sexual Quality of Life for Men-Who-Have-Sex-with-Men.

INTRODUCTION: With earlier prostate cancer (PCa) diagnosis and an increased focus on survivorship, post-treatment sexual quality of life (QoL) has become increasingly important. Research and validated instruments for sexual QoL assessment based on heterosexual samples have limited applicability for men-who-have-sex-with-men (MSM). AIM: We aimed to create a validated instrument for assessing sexual needs and concerns of MSM post-PCa treatment. Here we explore post-PCa treatment sexual concerns for a sample of MSM, as the first part of this multi-phase project. METHODS: Individual semi-structured interviews were conducted with 16 MSM face-to-face or via Internet-based video conferencing. Participants were asked open-ended questions about their experiences of sexual QoL following PCa. Interviews were recorded, transcribed verbatim, uploaded to NVivo 8(TM) , and analyzed using qualitative methodology. MAIN OUTCOME MEASURE: We have conducted semi-structure qualitative interviews on 16 MSM who were treated for PCa. Focus was on post-treatment sexual concerns. RESULTS: The following themes were inductively derived: (i) erectile, urinary, ejaculation, and orgasmic dysfunctions; (ii) challenges to intimate relationships; and (iii) lack of MSM-specific oncological and psychosocial support for PCa survivorship. Sexual practices pre-treatment ranked in order of frequency were masturbation, oral sex, and anal sex, an ordering that prevailed post-treatment. Sexual QoL decreased with erectile, urinary, and ejaculation dysfunctions. Post-treatment orgasms were compromised. Some single men and men in non-monogamous relationships reported a loss of confidence or difficulty meeting other men post-treatment. Limited access to targeted oncological and psychosocial supports posed difficulties in coping with PCa for MSM. CONCLUSIONS: The negative impact on sexual QoL can be severe for MSM and requires targeted attention. Penile-vaginal intercourse and erectile function have been the primary focus of sexual research and rehabilitation for men with PCa, and do not adequately reflect the sexual practices of MSM. Our findings suggest that future research dedicated to MSM with PCa is needed to incorporate their sexual practices and preferences specifically into treatment decisions, and that targeted oncological and psychosocial support services are also warranted.

Challenges in the delivery of peptide drugs: an industry perspective.

Due mainly to their poor stability and short plasma half-life, peptides are usually administered by injection, often several times daily. Injectable sustained-release formulations of peptides based on biodegradable polymer microparticles or implants early demonstrated the power of drug delivery technologies to enhance patient adherence and convenience, and increase safety and efficacy. Injectable sustained-release formulations are likely to remain a significant part of new peptide products. However, a new generation of technologies that enable solvent-free formulations and manufacturing processes, injection through narrow gauge needles and ready-to-use presentations will be increasingly used. In addition, the tremendous developments in noninvasive routes of delivery are likely to result in more and more peptides being delivered by the oral, transdermal, nasal or inhalation routes.