ARTICLE | doi:10.20944/preprints202003.0130.v1
Subject: Materials Science, Biomaterials Keywords: liposomes; polymersomes; filtration; freeze-thaw; membrane mechanics; encapsulation stability
Online: 8 March 2020 (04:23:34 CET)
Sterilisation and preservation of vesicle formulations are an important consideration for their viable manufacture for industry applications, particular those intended for medicinal use. Here we undertake an initial investigation of the stability of hybrid lipid – block copolymer vesicles to common sterilisation and preservation processes, with particular interest in how the block copolymer component might tune vesicle stability. We investigate two sizes of polybutadiene-block-poly(ethylene oxide) polymers (PBd12-PEO11 and PBd22-PEO14) mixed with the phospholipid POPC considering the encapsulation stability of a fluorescent cargo and the colloidal stability of vesicle size distributions. We find that autoclaving and lyophilisation cause complete loss of encapsulation stability under the conditions studied here. Filtering through 200 nm pores appears to be viable for sterilisation for all vesicle compositions with comparatively low release of encapsulated cargo, even for vesicle size distributions which extend beyond the 200 nm filter pore size. Freeze-thaw of vesicles also shows promise for preservation of hybrid vesicles with high block copolymer content. We discuss the process stability of hybrid vesicles in terms of the complex mechanical interplay between bending resistance, stretching elasticity and lysis strain of these membranes and propose strategies for future work to further enhance the process stability of these vesicle formulations.
REVIEW | doi:10.20944/preprints201810.0507.v1
Subject: Life Sciences, Other Keywords: liposomes, exosomes, extracellular vesicles, drug delivery, drug targeting, bioinspired systems, engineered systems.
Online: 22 October 2018 (15:35:20 CEST)
The similarities between exosomes and liposomes, together with the high organotropism of several types of exosomes, have recently prompted the development of engineered-exosomes or exosome-mimetics, which may be artificial (liposomal) or cell-derived vesicles, as advanced platforms for targeted drug delivery. Here we provide the current state-of-the-art of using exosome or exosome-inspired systems for drug delivery. We review the various approaches investigated and the shortcomings of each approach. Finally the challenges identified up-to-date in this field are summarized.
REVIEW | doi:10.20944/preprints202110.0060.v3
Subject: Biology, Plant Sciences Keywords: RNAi; dsRNA; silencing; encapsulation; liposomes; virus-like particles; polyplex nanoparticles; bio-clay; regulatory
Online: 13 October 2021 (15:39:34 CEST)
RNAi technology is a versatile, effective, safe, and eco-friendly alternative for crop protection. There is plenty of evidence of its use through host-induced gene silencing (HIGS) and spray-induced gene silencing (SIGS) techniques to control viruses, bacteria, fungi, insects, and nematodes. For SIGS, its most significant challenge is achieving stability and avoiding premature degradation of RNAi in the environment or during its absorption by the target organism. One alternative is encapsulation in liposomes, virus-like particles, polyplex nanoparticles, and bioclay, which can be obtained through the recombinant production of RNAi in vectors, transgenesis, and micro/nanoencapsulation. The materials must be safe, biodegradable, and stable in multiple chemical environments, favoring the controlled release of RNAi. Most of the current research on encapsulated RNAi focuses primarily on oral delivery to control insects by silencing essential genes. The regulation of RNAi technology focuses on risk assessment using different approaches; however, this technology has positive economic, environmental, and human health implications for its use in agriculture. The emergence of alternatives combining RNAi gene silencing with the induction of resistance in crops by elicitation and metabolic control is expected, as well as multiple silencing and biotechnological optimization of its large-scale production.
ARTICLE | doi:10.20944/preprints202106.0585.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Triamcinolone acetonide; Liposomes; Neovascular age related macular degeneration; Wet macular degeneration; Adjuvant therapy; Ranibizumab
Online: 23 June 2021 (12:56:55 CEST)
Novel strategies have been developed to reduce or to avoid the intravitreal injections (IVTs) of the antiangiogenic (ranibizumab; RBZ) and the anti-inflammatory (triamcinolone acetonide; TA) agents used to treat vitreoretinal diseases. One of the strategies include liposomes. In this study, it was evaluated the safety and efficacy of topical triamcinolone-loaded liposomes formulation (TALF) as an adjuvant to intravitreal RBZ therapy in treatment-naive patients with neovascular age related macular degeneration (nAMD). Subjects were randomly assigned to the RBZ-TALF or the RBZ-pro re nata (RBZ-PRN) group. Patients from the RBZ-TALF group were instructed to apply TALF for a 12-month period after a single dose of RBZ. Patients from the RBZ-PRN group received three monthly RBZ-IVTs. Retreatment with RBZ was considered in case of nAMD reactivation. Related to safety, non-ocular abnormalities were observed during TALF therapy. Owing to the efficacy, non-significant differences are identified in visual acuity or central foveal thickness when the RBZ-PRN and RBZ-TALF groups are compared. Importantly the average number of RBZ injections was significantly lower in the RBZ-TALF group (2.5 ± 1.4 vs 6.1 ± 1.3 IVTs; p=0004). Therefore, TALF used as an adjuvant to RBZ reduce the number of RBZ-IVTs retreatment with optimal visual and anatomic results.
REVIEW | doi:10.20944/preprints202108.0207.v1
Subject: Life Sciences, Biotechnology Keywords: ARV delivery; Biotechnology in ARV; Biological Barriers; Emulsions; Lipid nanoparticles; Liposomes; RNAi and ARV codelivery.
Online: 9 August 2021 (17:09:13 CEST)
Since HIV was first identified, and in a relatively short period of time, AIDS has become one of the most devastating infectious diseases of the 21st century. Classical antiretroviral therapies were a major step forward in disease treatment options, significantly improving the survival rates of HIV-infected individuals. Even though these therapies have greatly improved HIV clinical outcomes, antiretrovirals (ARV) feature biopharmaceutic and pharmacokinetic problems such as poor aqueous solubility, short half-life and poor penetration into HIV reservoir sites, which contribute to the sub-optimal efficacy of these regimens. To overcome some of these issues, novel nanotechnology-based strategies for ARV delivery towards HIV viral reservoirs have been proposed. The current review focus on the benefits of using lipid-based nanocarriers for tuning the physicochemical properties of ARVs to overcome biological barriers upon administration. Furthermore, a correlation of these properties and the potential therapeutic outcomes has been established. Biotechnological advancements using lipid nanocarriers for RNA interference delivery for the treatment of HIV infections were also discussed.
REVIEW | doi:10.20944/preprints202108.0447.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Interferons; IFNα; IFNß; IFNγ; antiviral; antiproliferative; immunomodulator; PEGylation; formulation; encapsulate IFNs; drug delivery system; liposomes; polymeric micelles; microparticles; nanoparticles
Online: 23 August 2021 (13:51:44 CEST)
Interferons (IFNs) are cytokines involved in the immune response that act on innate and adaptive immunity. These proteins are natural cell-signaling glycoproteins expressed in response to viral infections, tumors, and biological inducers and constitute the first line of defense of vertebrates against infectious agents. They have been marketed for more than 30 years with considerable impact on the global therapeutic protein market thanks to their diversity in terms of biological activities. They have been used as single agents or with combination treatment regimens, demonstrating promising clinical results, resulting in 22 different formulations approved by regulatory agencies. The 163 clinical trials with currently active IFNs reinforce their importance as therapeutics for human health. However, their application has presented difficulties due to the molecules’ size, sensitivity to degradation, and rapid elimination from the bloodstream. For some years now, work has been underway to obtain new drug delivery systems to provide adequate therapeutic concentrations for these cytokines, decrease their toxicity and prolong their half-life in the circulation. Although different research groups have presented various formulations that encapsulate IFNs, to date, there is no formulation approved for use in humans. The current review exhibits an updated summary of all encapsulation forms presented in the scientific literature for these cytokines IFNα, IFNß, and IFNγ, from the year 1996 to the year 2021, considering parameters such as: encapsulating matrix, route of administration, and encapsulation.
ARTICLE | doi:10.20944/preprints202101.0478.v1
Subject: Medicine & Pharmacology, Allergology Keywords: ocular drug delivery system; topical liposomes; posterior segment of the eye; safety and toler-ability; biologic activity; diabetic macular edema
Online: 25 January 2021 (10:48:51 CET)
Intravitreal injections (IVTs) of corticosteroids as triamcinolone acetonide (TA) are frequently used for the treatment of many vitreous and retinal disorders. However, IVTs are related to severe ocular complications. Lately, a topical ophthalmic TA loaded liposomes formulation (TALF) was designed to transport TA into the posterior segment of the eye when instilled in the ocular surface. To evaluate the safety, tolerability, and biologic activity of TALF, an animal study and a phase I clinical assay was performed. Moreover, four patients with diabetic macular edema (DME) were treated with TALF in order to explore the biologic activity of the formulation. No inflammation, lens opacity, swelling or intraocular pressure rising were recorded after the instillation of TALF in any of the animal or clinical study. Mainly, mild and transient adverse events such as dry eye (30%) and burning (30%) were reported. TALF improves significantly visual acuity and diminishes central foveal thickness in patients with DME. The current data demonstrate the safety, tolerability, and biologic activity of TALF. It seems that TALF can be used topically to treat vitreous and retinal diseases that respond to TA such as DME, avoiding the use of corticosteroids IVTs and its associated hazards.
ARTICLE | doi:10.20944/preprints202104.0512.v1
Subject: Materials Science, Biomaterials Keywords: hepatitis B virus (HBV); Myr47 lipopeptide; cellular uptake; liposomes; sodium taurocholate cotransporting polypeptide (NTCP); HBV surface antigen (HBsAg); apolipoprotein E (ApoE)
Online: 19 April 2021 (17:08:53 CEST)
Myr47 lipopeptide consisting of hepatitis B virus (HBV) pre-S1 domain (myristoylated 2-48 peptide) is a commercialized effective anti-HBV drug, preventing the interaction of HBV with sodium taurocholate cotransporting polypeptide (NTCP) on human hepatocytes, of which the activity requires both N-myristoylation residue and specific amino acid sequence. Meanwhile, we recently reported that Myr47 reduces the cellular uptake of HBV surface antigen (HBsAg, subviral particle of HBV) in the absence of NTCP expression (Somiya; et al. Virology 2016, 497, 23–32). In this study, we analyzed how Myr47 reduces the cellular uptake of lipid nanoparticles (including liposomes (LPs) and HBsAg) without NTCP expression. By using Myr47 mutants lacking the HBV infection inhibitory activity, they could reduce the cellular uptake of LPs in an N-myristoylation-dependent manner whereas in an amino acid sequence-independent manner. Moreover, Myr47 and its mutants could reduce the interaction of LPs with apolipoprotein E3 (ApoE3) in an N-myristoylation-dependent manner regardless of their amino acid sequences. From these results, N-myristoyl residue of lipopeptides generally could interfere the LPs/HBsAg-ApoE3 complex formation, thereby reducing the cellular uptake of LPs/HBsAg. When lipid nanoparticles are used as a DDS (drug delivery system) nanocarrier, the surface modification with lipopeptides may be a new method to inhibit unwanted cellular uptake of DDS nanocarriers by non-target cells.