Synthesis and Ex Vivo Trans-Corneal Permeation of Penetratin Analogues as Ophthalmic Carriers: Preliminary Results

Among enhancing strategies proposed in ocular drug delivery, a rising interest is directed to cell penetrating peptides (CPPs), amino acid short sequences primarily known for their intrinsic ability to cell internalization and, by extension, to cross biological barriers. In fact, CPPs may be considered as carrier for delivering therapeutic agents across biological membranes, including ocular tissues. Several CPPs have been proposed in ophthalmic delivery, and, among them, penetratin (PNT), a 16-amino acids natural peptide, stands out. Therefore, we describe the synthesis via the mimotopic approach of short fluorescently labeled analogues of both PNT and its reversed sequence PNT-R. Their ability to cross ocular membranes was checked ex vivo using freshly explanted porcine cornea. Furthermore, some sequences were studied by circular dichroism. Despite the hydrophilic nature and the relatively high molecular weight (approx. 1.6 kDa), all analogues showed a not negligible trans-corneal diffusion, indicating a partial preservation of penetration activity, even if no sequences reached the noteworthy ability of PNT. It was not possible to find a correlation between structure and corneal penetration ability, and further studies, exploring peptides distribution within corneal layers, for example using imaging techniques, deserve to be performed to figure out a possible difference in intracellular delivery.

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Development and Characterization of Liposomal formulation for ophthalmic delivery of Prednisolone Acetate

International Journal of Pharmaceutical Sciences and Drug Research ◽

10.25004/ijpsdr.2020.120212 ◽

2020 ◽

pp. 175-180

Author(s):

Hardik Joshi ◽

Pragna Shelat ◽

Divyang Dave

Keyword(s):

Ex Vivo ◽

Chorioallantoic Membrane ◽

Entrapment Efficiency ◽

Drug Carriers ◽

Stability Study ◽

Prednisolone Acetate ◽

Ocular Irritation ◽

Ophthalmic Delivery ◽

Corneal Permeation

Liposomal vesicular drug carriers for ocular delivery have earned a wide potential nowadays. Prednisolone Acetate liposome as ocular drug carriers have been demonstrated to be a useful mode to ameliorate bioavailability and patient abidance. Liposome was prepared by lipid extruder method. Liposome were characterized for entrapment efficiency (EE %), vesicle size, surface morphology and in vitro drug release. An ex vivo corneal permeation study was performed to determine the level of drug in the external eye tissue of goat and an ocular irritation assessment was done by Hen’s Egg Test - Chorioallantoic Membrane (HET-CAM) method. The optimized formulation of liposome had shown acceptable viscosity (1.21 ± 0.03 cps), refractive index (1.47±0.001), osmolarity (303 ± 3 mOsm) and pH measurement (7.12 ± 0.09). Liposome as drug delivery carriers were evidenced to be a anticipating impendent to enhance corneal contact and penetration as well as retention time in the eye ensuing in a prolonged action and enhanced bioavailability. The results of stability study exhibited stable profile of developed liposomes.

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Hybrid Cyclobutane/Proline-Containing Peptidomimetics: The Conformational Constraint Influences Their Cell-Penetration Ability

International Journal of Molecular Sciences ◽

10.3390/ijms22105092 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5092

Author(s):

Ona Illa ◽

Jimena Ospina ◽

José-Emilio Sánchez-Aparicio ◽

Ximena Pulido ◽

María Ángeles Abengozar ◽

...

Keyword(s):

Amino Acid ◽

Cell Penetrating Peptides ◽

Cell Uptake ◽

Relevant Parameter ◽

Intracellular Accumulation ◽

Peptide Backbone ◽

New Family ◽

Cell Line Hela ◽

Penetration Ability ◽

Tumoral Cell

A new family of hybrid β,γ-peptidomimetics consisting of a repetitive unit formed by a chiral cyclobutane-containing trans-β-amino acid plus a Nα-functionalized trans-γ-amino-l-proline joined in alternation were synthesized and evaluated as cell penetrating peptides (CPP). They lack toxicity on the human tumoral cell line HeLa, with an almost negligible cell uptake. The dodecapeptide showed a substantial microbicidal activity on Leishmania parasites at 50 µM but with a modest intracellular accumulation. Their previously published γ,γ-homologues, with a cyclobutane γ-amino acid, showed a well-defined secondary structure with an average inter-guanidinium distance of 8–10 Å, a higher leishmanicidal activity as well as a significant intracellular accumulation. The presence of a very rigid cyclobutane β-amino acid in the peptide backbone precludes the acquisition of a defined conformation suitable for their cell uptake ability. Our results unveiled the preorganized charge-display as a relevant parameter, additional to the separation among the charged groups as previously described. The data herein reinforce the relevance of these descriptors in the design of CPPs with improved properties.

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High-Resolution Magnetic Resonance Imaging of the Human Median Nerve

Neurorehabilitation and Neural Repair ◽

10.1177/0888439004267074 ◽

2004 ◽

Vol 18 (2) ◽

pp. 80-87 ◽

Cited By ~ 11

Author(s):

Archie Heddings ◽

Mehmet Bilgen ◽

Randolph Nudo ◽

Bruce Toby ◽

Terence McIff ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

High Resolution ◽

Peripheral Nerve ◽

Median Nerve ◽

Ex Vivo ◽

Imaging Techniques ◽

Proton Density ◽

Resonance Imaging ◽

Imaging Protocols

Objectives. It is widely accepted that peripheral nerve repairs performed within 6 weeks of injury have much better outcomes than those performed at later dates. However, there is no diagnostic technique that can determine if a traumatic peripheral nerve injury requires surgical intervention in the early postinjury phase. The objective of this article was to determine whether novel, noninvasive magnetic resonance imaging techniques could demonstrate the microstructure of human peripheral nerves that is necessary for determining prognosis and determining if surgery is indicated following traumatic injury. Methods. Ex vivo magnetic resonance imaging protocols were developed on a 9.4-T research scanner using spin-echo proton density and gradient-echo imaging sequences and a specially designed, inductively coupled radio frequency coil. These imaging protocols were applied to in situ imaging of the human median nerve in 4 fresh-frozen cadaver arms. Results. Noninvasive high-resolution images of the human median nerve were obtained. Structures in the nerve that were observed included fascicles, interfascicular epineurium, perineurium, and intrafascicular septations. Conclusion. Application of these imaging techniques to clinical scanners could provide physicians with a tool that is capable of grading the severity of nerve injuries and providing indications for surgery in the early postinjury phase.

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In Vivo Imaging of Peripheral Benzodiazepine Receptors in Mouse Lungs: A Biomarker of Inflammation

Molecular Imaging ◽

10.2310/7290.2005.05133 ◽

2005 ◽

Vol 4 (4) ◽

pp. 7290.2005.05133 ◽

Cited By ~ 19

Author(s):

Matthew J. Hardwick ◽

Ming-Kai Chen ◽

Kwamena Baidoo ◽

Martin G. Pomper ◽

Tomás R. Guilarte

Keyword(s):

In Vivo Imaging ◽

Ex Vivo ◽

Inflammatory Diseases ◽

Imaging Techniques ◽

Benzodiazepine Receptors ◽

Small Animal ◽

Small Animal Pet ◽

Planar Imaging ◽

Peripheral Benzodiazepine Receptors

The ability to visualize the immune response with radioligands targeted to immune cells will enhance our understanding of cellular responses in inflammatory diseases. Peripheral benzodiazepine receptors (PBR) are present in monocytes and neutrophils as well as in lung tissue. We used lipopolysaccharide (LPS) as a model of inflammation to assess whether the PBR could be used as a noninvasive marker of inflammation in the lungs. Planar imaging of mice administrated 10 or 30 mg/kg LPS showed increased [123I]-( R)-PK11195 radioactivity in the thorax 2 days after LPS treatment relative to control. Following imaging, lungs from control and LPS-treated mice were harvested for ex vivo gamma counting and showed significantly increased radioactivity above control levels. The specificity of the PBR response was determined using a blocking dose of nonradioactive PK11195 given 30 min prior to radiotracer injection. Static planar images of the thorax of nonradioactive PK11195 pretreated animals showed a significantly lower level of radiotracer accumulation in control and in LPS-treated animals ( p < .05). These data show that LPS induces specific increases in PBR ligand binding in the lungs. We also used in vivo small-animal PET studies to demonstrate increased [11C]-( R)-PK11195 accumulation in the lungs of LPS-treated mice. This study suggests that measuring PBR expression using in vivo imaging techniques may be a useful biomarker to image lung inflammation.

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β-Lactamase Tools for Establishing Cell Internalization and Cytosolic Delivery of Cell Penetrating Peptides

Biomolecules ◽

10.3390/biom8030051 ◽

2018 ◽

Vol 8 (3) ◽

pp. 51 ◽

Cited By ~ 5

Author(s):

Shane Stone ◽

Tatjana Heinrich ◽

Suzy Juraja ◽

Jiulia Satiaputra ◽

Clinton Hall ◽

...

Keyword(s):

Functional Characterization ◽

Cell Penetrating Peptides ◽

Stable Cell Line ◽

Intracellular Space ◽

Biologically Relevant ◽

Cell Internalization ◽

Cytosolic Delivery ◽

Cell Penetrating ◽

Split Protein

The ability of cell penetrating peptides (CPPs) to deliver biologically relevant cargos into cells is becoming more important as targets in the intracellular space continue to be explored. We have developed two assays based on CPP-dependent, intracellular delivery of TEM-1 β-lactamase enzyme, a functional biological molecule comparable in size to many protein therapeutics. The first assay focuses on the delivery of full-length β-lactamase to evaluate the internalization potential of a CPP sequence. The second assay uses a split-protein system where one component of β-lactamase is constitutively expressed in the cytoplasm of a stable cell line and the other component is delivered by a CPP. The delivery of a split β-lactamase component evaluates the cytosolic delivery capacity of a CPP. We demonstrate that these assays are rapid, flexible and have potential for use with any cell type and CPP sequence. Both assays are validated using canonical and novel CPPs, with limits of detection from <500 nM to 1 µM. Together, the β-lactamase assays provide compatible tools for functional characterization of CPP activity and the delivery of biological cargos into cells.

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EANM recommendations based on systematic analysis of small animal radionuclide imaging in inflammatory musculoskeletal diseases

EJNMMI Research ◽

10.1186/s13550-021-00820-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Erik H. J. G. Aarntzen ◽

Edel Noriega-Álvarez ◽

Vera Artiko ◽

André H. Dias ◽

Olivier Gheysens ◽

...

Keyword(s):

Molecular Imaging ◽

Radionuclide Imaging ◽

Musculoskeletal Diseases ◽

Ex Vivo ◽

Imaging Techniques ◽

Large Body ◽

Therapeutic Interventions ◽

Histopathological Analysis ◽

Complementary Value

AbstractInflammatory musculoskeletal diseases represent a group of chronic and disabling conditions that evolve from a complex interplay between genetic and environmental factors that cause perturbations in innate and adaptive immune responses. Understanding the pathogenesis of inflammatory musculoskeletal diseases is, to a large extent, derived from preclinical and basic research experiments. In vivo molecular imaging enables us to study molecular targets and to measure biochemical processes non-invasively and longitudinally, providing information on disease processes and potential therapeutic strategies, e.g. efficacy of novel therapeutic interventions, which is of complementary value next to ex vivo (post mortem) histopathological analysis and molecular assays. Remarkably, the large body of preclinical imaging studies in inflammatory musculoskeletal disease is in contrast with the limited reports on molecular imaging in clinical practice and clinical guidelines. Therefore, in this EANM-endorsed position paper, we performed a systematic review of the preclinical studies in inflammatory musculoskeletal diseases that involve radionuclide imaging, with a detailed description of the animal models used. From these reflections, we provide recommendations on what future studies in this field should encompass to facilitate a greater impact of radionuclide imaging techniques on the translation to clinical settings.

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Towards Clinical Translation of LED-Based Photoacoustic Imaging: A Review

Sensors ◽

10.3390/s20092484 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2484 ◽

Cited By ~ 10

Author(s):

Yunhao Zhu ◽

Ting Feng ◽

Qian Cheng ◽

Xueding Wang ◽

Sidan Du ◽

...

Keyword(s):

Ex Vivo ◽

Photoacoustic Imaging ◽

Imaging Techniques ◽

Clinical Translation ◽

Key Factors ◽

Pilot Studies ◽

History Of ◽

Molecular Components ◽

Clinical Potential

Photoacoustic imaging, with the capability to provide simultaneous structural, functional, and molecular information, is one of the fastest growing biomedical imaging modalities of recent times. As a hybrid modality, it not only provides greater penetration depth than the purely optical imaging techniques, but also provides optical contrast of molecular components in the living tissue. Conventionally, photoacoustic imaging systems utilize bulky and expensive class IV lasers, which is one of the key factors hindering the clinical translation of this promising modality. Use of LEDs which are portable and affordable offers a unique opportunity to accelerate the clinical translation of photoacoustics. In this paper, we first review the development history of LED as an illumination source in biomedical photoacoustic imaging. Key developments in this area, from point-source measurements to development of high-power LED arrays, are briefly discussed. Finally, we thoroughly review multiple phantom, ex-vivo, animal in-vivo, human in-vivo, and clinical pilot studies and demonstrate the unprecedented preclinical and clinical potential of LED-based photoacoustic imaging.

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Electrochemical degradation and saponification of porcine adipose tissue

Scientific Reports ◽

10.1038/s41598-020-76678-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Tiffany T. Pham ◽

Anna M. Stokolosa ◽

Pamela A. Borden ◽

Kyle D. Hansen ◽

Ellen M. Hong ◽

...

Keyword(s):

Adipose Tissue ◽

Subcutaneous Adipose Tissue ◽

Ex Vivo ◽

Imaging Techniques ◽

Low Cost ◽

Electrical Potential ◽

Body Contouring ◽

Past Century ◽

Ph Gradients ◽

Subcutaneous Adipose

AbstractBody contouring achieved via subcutaneous adipose tissue reduction has notably advanced over the past century, from suction assisted lipectomy to techniques with reduced degrees of invasiveness including laser, radiofrequency, high frequency focused ultrasound, cryolipolysis, and drug-based injection approaches. These costly techniques have focused on damaging adipocyte cell membranes, hydrolyzing triglycerides (TGs), or inducing apoptosis. Here, we present a simple, low-cost technique, termed electrochemical lipolysis (ECLL). During ECLL, saline is injected into the subcutaneous adipose tissue, followed by insertion of needle electrodes and application of an electrical potential. Electrolysis of saline creates localized pH gradients that drive adipocyte death and saponification of TGs. Using pH mapping, various optical imaging techniques, and biochemical assays, we demonstrate the ability of ECLL to induce acid and base injury, cell death, and the saponification of triglycerides in ex vivo porcine adipose tissue. We define ECLL’s potential role as a minimally-invasive, ultra-low-cost technology for reducing and contouring adipose tissue, and present ECLL as a potential new application of an emerging electrochemical redox based treatment modality.

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