Non-invasive delivery strategies for biologics

Oral administration microrobots for drug delivery

Oral administration is the most simple, noninvasive, convenient treatment. With the increasing demands on the targeted drug delivery, the traditional oral treatment now is facing some challenges: 1) biologics how to implement the oral treatment and ensure the bioavailability is not lower than the subcutaneous injections; 2) How to achieve targeted therapy of some drugs in the gastrointestinal tract? Based on these two issues, drug delivery microrobots have shown great application prospect in oral drug delivery due to their characteristics of flexible locomotion or driven ability. Therefore, this paper summarizes various drug delivery microrobots developed in recent years and divides them into four categories according to different driving modes: magnetic-controlled drug delivery microrobots, anchored drug delivery microrobots, self-propelled drug delivery microrobots and biohybrid drug delivery microrobots. As oral drug delivery microrobots involve disciplines such as materials science, mechanical engineering, medicine, and control systems, this paper begins by introducing the gastrointestinal barriers that oral drug delivery must overcome. Subsequently, it provides an overview of typical materials involved in the design process of oral drug delivery microrobots. To enhance readers' understanding of the working principles and design process of oral drug delivery microrobots, we present a guideline for designing such microrobots. Furthermore, the current development status of various types of oral drug delivery microrobots is reviewed, summarizing their respective advantages and limitations. Finally, considering the significant concerns regarding safety and clinical translation, we discuss the challenges and prospections of clinical translation for various oral drug delivery microrobots presented in this paper, providing corresponding suggestions for addressing some existing challenges.

Stabilization of Non-Native Folds and Programmable Protein Gelation in Compositionally Designed Deep Eutectic Solvents

Proteins are adjustable units from which biomaterials with designed properties can be developed. However, non-native folded states with controlled topologies are hardly accessible in aqueous environments, limiting their prospects as building blocks. Here, we demonstrate the ability of a series of anhydrous deep eutectic solvents (DESs) to precisely control the conformational landscape of proteins. We reveal that systematic variations in the chemical composition of binary and ternary DESs dictate the stabilization of a wide range of conformations, that is, compact globular folds, intermediate folding states, or unfolded chains, as well as controlling their collective behavior. Besides, different conformational states can be visited by simply adjusting the composition of ternary DESs, allowing for the refolding of unfolded states and vice versa. Notably, we show that these intermediates can trigger the formation of supramolecular gels, also known as eutectogels, where their mechanical properties correlate to the folding state of the protein. Given the inherent vulnerability of proteins outside the native fold in aqueous environments, our findings highlight DESs as tailorable solvents capable of stabilizing various non-native conformations on demand through solvent design.

Cell-drug conjugates

By combining living cells with therapeutics, cell-drug conjugates can potentiate the functions of both components, particularly for applications in drug delivery and therapy. The conjugates can be designed to persist in the bloodstream, undergo chemotaxis, evade surveillance by the immune system, proliferate, or maintain or transform their cellular phenotypes. In this Review, we discuss strategies for the design of cell-drug conjugates with specific functions, the techniques for their preparation, and their applications in the treatment of cancers, autoimmune diseases and other pathologies. We also discuss the translational challenges and opportunities of this class of drug-delivery systems and therapeutics.

Changing the location of proteins on the cell surface is a promising strategy for modulating T cell functions

Targeting immune receptors on T cells is a common strategy to treat cancer and autoimmunity. Frequently, this is accomplished through monoclonal antibodies targeting the ligand binding sites of stimulatory or inhibitory co-receptors. Blocking ligand binding prevents downstream signalling and modulates specific T cell functions. Since 1985, the FDA has approved over 100 monoclonal antibodies against immune receptors. This therapeutic approach significantly improved the care of patients with numerous immune-related conditions; however, many patients are unresponsive, and some develop immune-related adverse events. One reason for that is the lack of consideration for the localization of these receptors on the cell surface of the immune cells in the context of the immune synapse. In addition to blocking ligand binding, changing the location of these receptors on the cell surface within the different compartments of the immunological synapse could serve as an alternative, efficient, and safer approach to treating these patients. This review discusses the potential therapeutic advantages of altering proteins' localization within the immune synapse and summarizes published work in this field. It also discusses the novel use of bispecific antibodies to induce the clustering of receptors on the cell surface. It presents the rationale for developing novel antibodies, targeting the organization of signalling receptor complexes on the cell surface. This approach offers an innovative and emerging technology to treat cancer patients resistant to current immunotherapies.

Data-driven development of an oral lipid-based nanoparticle formulation of a hydrophobic drug

Due to its cost-effectiveness, convenience, and high patient adherence, oral drug administration normally remains the preferred approach. Yet, the effective delivery of hydrophobic drugs via the oral route is often hindered by their limited water solubility and first-pass metabolism. To mitigate these challenges, advanced delivery systems such as solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) have been developed to encapsulate hydrophobic drugs and enhance their bioavailability. However, traditional design methodologies for these complex formulations often present intricate challenges because they are restricted to a relatively narrow design space. Here, we present a data-driven approach for the accelerated design of SLNs/NLCs encapsulating a model hydrophobic drug, cannabidiol, that combines experimental automation and machine learning. A small subset of formulations, comprising 10% of all formulations in the design space, was prepared in-house, leveraging miniaturized experimental automation to improve throughput and decrease the quantity of drug and materials required. Machine learning models were then trained on the data generated from these formulations and used to predict properties of all SLNs/NLCs within this design space (i.e., 1215 formulations). Notably, formulations predicted to be high-performers via this approach were confirmed to significantly enhance the solubility of the drug by up to 3000-fold and prevented degradation of drug. Moreover, the high-performance formulations significantly enhanced the oral bioavailability of the drug compared to both its free form and an over-the-counter version. Furthermore, this bioavailability matched that of a formulation equivalent in composition to the FDA-approved product, Epidiolex®.

Leucine as a moisture-protective excipient in spray-dried protein/trehalose formulation

The incorporation of leucine (Leu), a hydrophobic amino acid, into pharmaceutically relevant particles via spray-drying can improve the physicochemical and particulate properties, stability, and ultimately bioavailability of the final product. More specifically, Leu has been proposed to form a shell on the surface of spray-dried (SD) particles. The aim of this study was to explore the potential of Leu in the SD protein/trehalose (Tre) formulation to control the water uptake and moisture-induced recrystallization of amorphous Tre, using lysozyme (LZM) as a model protein. LZM/Tre (1:1, w/w) were dissolved in water with varied amounts of Leu (0 - 40%, w/w) and processed by spray-drying. The solid form, residual moisture content (RMC), hygroscopicity, and morphology of SD LZM/Tre/Leu powders were evaluated, before and after storage under 22°C/55% RH conditions for 90 and 180 days. The X-ray powder diffraction results showed that Leu was in crystalline form when the amount of Leu in the formulation was at least 20% (w/w). Thermo-gravimetric analysis and scanning electron microscopy results showed that 0%, 5%, and 10% Leu formulations led to comparable RMC and raisin-like round particles. In contrast, higher Leu contents resulted in a lower RMC and increased surface corrugation of the SD particles. Dynamic vapor sorption analysis showed that in the 0% Leu formulation, partial recrystallization of amorphous Tre to crystalline Tre·dihydrate occurred, and the addition of as little as 5% Leu could inhibit the recrystallization of amorphous Tre during the water sorption/desorption cycle. In addition, after storage, formulations with higher Leu contents resulted in less water uptake. Rather than recrystallization of amorphous Tre in 0%, 5%, and 10% Leu formulations, recrystallization of amorphous Leu was observed in both 5% and 10% Leu formulations after storage. In summary, our study demonstrated that the addition of Leu has the potential to reduce water uptake and inhibit moisture-induced recrystallization of amorphous Tre in the SD protein/Tre powder system.

Aqueous photo-RAFT polymerization under ambient conditions: synthesis of protein-polymer hybrids in open air

A photoinduced reversible addition-fragmentation chain-transfer (photo-RAFT) polymerization technique in the presence of sodium pyruvate (SP) and pyruvic acid derivatives was developed. Depending on the wavelength of light used, SP acted as a biocompatible photoinitiator or promoter for polymerization, allowing rapid open-to-air polymerization in aqueous media. Under UV irradiation (370 nm), SP decomposes to generate CO2 and radicals, initiating polymerization. Under blue (450 nm) or green (525 nm) irradiation, SP enhances the polymerization rate via interaction with the excited state RAFT agent. This method enabled the polymerization of a range of hydrophilic monomers in reaction volumes up to 250 mL, eliminating the need to remove radical inhibitors from the monomers. In addition, photo-RAFT polymerization using SP allowed for the facile synthesis of protein-polymer hybrids in short reaction times (<1 h), low organic content (≤16%), and without rigorous deoxygenation and the use of transition metal photocatalysts. Enzymatic studies of a model protein (chymotrypsin) showed that despite a significant loss of protein activity after conjugation with RAFT chain transfer agents, the grafting polymers from proteins resulted in a 3-4-fold recovery of protein activity.

Breaking barriers: bacterial-microalgae symbiotic systems as a probiotic delivery system

The gut microbiota is one of the essential contributors of the pathogenesis and progress of inflammatory bowel disease (IBD). Compared with first-line drug therapy, probiotic supplementation has emerged as a viable and secure therapeutic approach for managing IBD through the regulation of both the immune system and gut microbiota. Nevertheless, the efficacy of oral probiotic supplements is hindered by their susceptibility to the gastrointestinal barrier, leading to diminished bioavailability and restricted intestinal colonization. Here, we developed a bacteria-microalgae symbiosis system (EcN-SP) for targeted intestinal delivery of probiotics and highly effective treatment of colitis. The utilization of mircroalge Spirulina platensis (SP) as a natural carrier for the probiotic Escherichia coli Nissle 1917 (EcN) demonstrated potential benefits in promoting EcN proliferation, facilitating effective intestinal delivery and colonization. The alterations in the binding affinity of EcN-SP within the gastrointestinal environment, coupled with the distinctive structural properties of the SP carrier, served to overcome gastrointestinal barriers, minimizing transgastric EcN loss and enabling sustained intestinal retention and colonization. The oral administration of EcN-SP could effectively treat IBD by reducing the expression of intestinal inflammatory factors, maintaining the intestinal barrier and regulating the balance of gut microbiota. This probiotic delivery approach is inspired by symbiotic interactions found in nature and offers advantages in terms of feasibility, safety, and efficacy, thus holding significant promise for the management of gastrointestinal disorders.

Amino acids as stabilizers for lysozyme during the spray-drying process and storage

Amino acids (AAs) have been used as excipients in protein formulations both in solid and liquid state products due to their stabilizing effect. However, the mechanisms by which they can stabilize a protein have not been fully elucidated yet. The purpose of this study was to investigate the effect of AAs with distinct physicochemical properties on the stability of a model protein (lysozyme, LZM) during the spray-drying process and subsequent storage. Molecular descriptor based multivariate data analysis was used to select distinct AAs from the group of 20 natural AAs. Then, LZM and the five selected AAs (1:1 wt ratio) were spray-dried (SD). The solid form, residual moisture content (RMC), hygroscopicity, morphology, secondary/tertiary structure and enzymatic activity of LZM were evaluated before and after storage under 40 °C/75 % RH for 30 days. Arginine (Arg), leucine (Leu), glycine (Gly), tryptophan (Trp), aspartic acid (Asp) were selected because of their distinct properties by using principal component analysis (PCA). The SD LZM powders containing Arg, Trp, or Asp were amorphous, while SD LZM powders containing Leu or Gly were crystalline. Recrystallization of Arg, Trp, Asp and polymorph transition of Gly were observed after the storage under accelerated conditions. The morphologies of the SD particles vary upon the different AAs formulated with LZM, implying different drying kinetics of the five model systems. A tertiary structural change of LZM was observed in the SD powder containing Arg, while a decrease in the enzymatic activity of LZM was observed in the powders containing Arg or Asp after the storage. This can be attributed to the extremely basic and acidic conditions that Arg and Asp create, respectively. This study suggests that when AAs are used as stabilizers instead of traditional disaccharides, not only do classic vitrification theory and water replacement theory play a role, but the microenvironmental pH conditions created by basic or acidic AAs in the starting solution or during the storage of solid matter are also crucial for the stability of SD protein products.

Enhancing the Therapeutic Efficacy of GLP-1 for Hyperglycemia Treatment: Overcoming Barriers of Oral Gene Therapy with Taurocholic Acid-Conjugated Protamine Sulfate and Calcium Phosphate

Activating the glucagon-like peptide-1 (GLP-1) receptor by oral nucleic acid delivery would be a promising treatment strategy against hyperglycemia due to its various therapeutic actions. However, GLP-1 receptor agonists are effective only in subcutaneous injections because they face multiple barriers due to harsh gastrointestinal tract (GIT) conditions before reaching the site of action. The apical sodium bile acid transporter (ASBT) pathway at the intestinal site could be an attractive target to overcome the problem. Herein, we used our previously established multimodal carrier system utilizing bile salt, protamine sulfate, and calcium phosphate as excipients (PTCA) and the GLP-1 gene as an active ingredient (GENE) to test the effects of different formulation doses against diabetes and obesity. The carrier system demonstrated the ability to protect the GLP-1 model gene encoded within the plasmid at the GIT and transport it via ASBT at the target site. A single oral dose, regardless of quantity, showed the generation of GLP-1 and insulin from the body and maintained the normoglycemic condition by improving insulin sensitivity and blood sugar tolerance for a prolonged period. This oral gene therapy approach shows significantly higher therapeutic efficacy in preclinical studies than currently available US Food and Drug Administration-approved GLP-1 receptor agonists such as semaglutide and liraglutide. Also, a single oral dose of GENE/PTCA is more effective than 20 insulin injections. Our study suggests that oral GENE/PTCA formulation could be a promising alternative to injection-based therapeutics for diabetics, which is effective in long-term treatment and has been found to be highly safe in all aspects of toxicology.

Evaluating the oral delivery of GalNAc-conjugated siRNAs in rodents and non-human primates

Oral delivery is the most widely used and convenient route of administration of medicine. However, oral administration of hydrophilic macromolecules is commonly limited by low intestinal permeability and pre-systemic degradation in the gastrointestinal (GI) tract. Overcoming some of these challenges allowed emergence of oral dosage forms of peptide-based drugs in clinical settings. Antisense oligonucleotides (ASOs) have also been investigated for oral administration but despite the recent progress, the bioavailability remains low. Given the advancement with highly potent and durable trivalent N-acetylgalactosamine (GalNAc)-conjugated small interfering RNAs (siRNAs) via subcutaneous (s.c.) injection, we explored their activities after oral administration. We report robust RNA interference (RNAi) activity of orally administrated GalNAc-siRNAs co-formulated with permeation enhancers (PEs) in rodents and non-human primates (NHPs). The relative bioavailability calculated from NHP liver exposure was <2.0% despite minimal enzymatic degradation in the GI. To investigate the impact of oligonucleotide size on oral delivery, highly specific GalNAc-conjugated single-stranded oligonucleotides known as REVERSIRs with different lengths were employed and their activities for reversal of RNAi effect were monitored. Our data suggests that intestinal permeability is highly influenced by the size of oligonucleotides. Further improvements in the potency of siRNA and PE could make oral delivery of GalNAc-siRNAs as a practical solution.

Patient Experience with the SensoReady® Autoinjector Pen versus a Comparator Device: Results from a Canadian Patient Survey in Rheumatoid Arthritis and Crohn´s Disease

Purpose

Medication delivery device design impacts treatment satisfaction, adherence, and compliance in patients receiving biologics. This survey assessed autoinjector attributes that are important to patients, and assessed patient perceptions and preferences between an adalimumab biosimilar autoinjector (Hyrimoz® SensoReady® Pen [SDZ-ADL pen]) and the reference adalimumab autoinjector (Humira® Pen [ref-ADL pen]) in patients with rheumatoid arthritis (RA) or Crohn's disease (CD) in Canada.

Patients and Methods

In this survey, adult patients were recruited for web-assisted telephone interviews. Patients had ≥ 3 months' experience with the ref-ADL pen and 1-12 months' experience with the SDZ-ADL pen.

Results

The survey included 120 patients with RA (n = 32) or CD (n = 88). Mean experience with the ref-ADL pen was 7 years for RA or 5 years for CD vs 9 months with the SDZ-ADL pen. The most important autoinjector attributes were the ability to use the pen independently and the ease and simplicity of self-injection. When comparing the two autoinjectors, patients significantly preferred the SDZ-ADL pen over the ref-ADL pen for nearly every attribute evaluated, with the greatest differences reported for visual and audible feedback mechanisms, ease of self-injection, and ability to use the device independently. Overall, 82% of patients preferred the SDZ-ADL pen over the ref-ADL pen, with buttonless activation and less injection pain being the main drivers for this preference.

Conclusion

Patients with RA or CD indicated a preference for the SDZ-ADL pen over the ref-ADL pen, independent of the duration of use of the pen. The preference for a biosimilar device within 1 year of switching provides reassurance of rapid patient acceptance of biosimilars and may simplify the switching process. These results confirm the importance of ensuring autoinjector design supports independent self-administration of medication and align with previous data showing high patient satisfaction with the SDZ-ADL pen.

Pharmaceutical and biotech industry perspectives on optimizing patient experience and treatment adherence through subcutaneous drug delivery design

Subcutaneous (SC) drug delivery can be a safe, effective alternative to the traditional intravenous route of administration, potentially offering notable advantages for both patients and healthcare providers. The SC Drug Development & Delivery Consortium convened in 2018 to raise awareness of industry challenges to advance the development of patient-centric SC drug delivery strategies. The SC Consortium identified better understanding of patient preferences and perspectives as necessary to optimize SC product design attributes and help guide design decisions during SC product development. This manuscript provides a comprehensive overview of patient-centric factors for consideration in the SC drug delivery design and development process with the aim of establishing a foundation of existing knowledge for patient experiences related to SC drug delivery. This overview is informed by the outcomes of a multi-step survey of Consortium members and key pharmaceutical stakeholders. Framed in the context of the patient's treatment journey, the survey findings offer future perspectives to fill data gaps to advance patient-centric SC drug delivery.

Ingestible Artificial Urinary Biomarker Probes for Urine Test of Gastrointestinal Cancer

Although colorectal cancer diagnosed at an early stage shows high curability, methods simultaneously possessing point-of-care testing ability and high sensitivity are limited. Here, an orally deliverable biomarker-activatable probe (termed as HATS) for early detection of orthotopic tumors via remote urinalysis is presented. To enable its oral delivery to the colon, HATS is designed to have remarkable resistance to acidity and digestive enzymes in the stomach and small intestine and negligible intestinal absorption. Upon reaction with a cancer biomarker in the colon segment, HATS releases a small fragment of tetrazine that can transverse the intestinal barrier, enter blood circulation, and ultimately undergo renal clearance to urine. Subsequently, the urinary tetrazine fragment is detected by bioorthogonal reaction with trans-cyclooctene-caged resorufin (TCO-Reso) to afford a rapid and specific fluorescence enhancement of TCO-Reso. Such signal readout is correlated with the urinary tetrazine concentration and thus measures the level of cancer biomarkers in the colon. HATS-based optical urinalysis detects orthotopic colon tumors two weeks earlier than clinical serological tests and can be developed to a point-of-care paper test. Thereby, HATS-based urinalysis provides a non-invasive and sensitive approach to cancer screening at low-resource settings.

Antidepressant-induced membrane trafficking regulates blood-brain barrier permeability

As the most prescribed psychotropic drugs in current medical practice, antidepressant drugs (ADs) of the selective serotonin reuptake inhibitor (SSRI) class represent prime candidates for drug repurposing. The mechanisms underlying their mode of action, however, remain unclear. Here, we show that common SSRIs and selected representatives of other AD classes bidirectionally regulate fluid-phase uptake at therapeutic concentrations and below. We further characterize membrane trafficking induced by a canonical SSRI fluvoxamine to show that it involves enhancement of clathrin-mediated endocytosis, endosomal system, and exocytosis. RNA sequencing analysis showed few fluvoxamine-associated differences, consistent with the effect being independent of gene expression. Fluvoxamine-induced increase in membrane trafficking boosted transcytosis in cell-based blood-brain barrier models, while a single injection of fluvoxamine was sufficient to enable brain accumulation of a fluid-phase fluorescent tracer in vivo. These findings reveal modulation of membrane trafficking by ADs as a possible cellular mechanism of action and indicate their clinical repositioning potential for regulating drug delivery to the brain.

Inhibition of DEF-p65 Interactions as a Potential Avenue to Suppress Tumor Growth in Pancreatic Cancer

The limited success of current targeted therapies for pancreatic cancer underscores an urgent demand for novel treatment modalities. The challenge in mitigating this malignancy can be attributed to the digestive organ expansion factor (DEF), a pivotal yet underexplored factor in pancreatic tumorigenesis. The study uses a blend of in vitro and in vivo approaches, complemented by the theoretical analyses, to propose DEF as a promising anti-tumor target. Analysis of clinical samples reveals that high expression of DEF is correlated with diminished survival in pancreatic cancer patients. Crucially, the depletion of DEF significantly impedes tumor growth. The study further discovers that DEF binds to p65, shielding it from degradation mediated by the ubiquitin-proteasome pathway in cancer cells. Based on these findings and computational approaches, the study formulates a DEF-mimicking peptide, peptide-031, designed to disrupt the DEF-p65 interaction. The effectiveness of peptide-031 in inhibiting tumor proliferation has been demonstrated both in vitro and in vivo. This study unveils the oncogenic role of DEF while highlighting its prognostic value and therapeutic potential in pancreatic cancer. In addition, peptide-031 is a promising therapeutic agent with potent anti-tumor effects.

Verapamil-Loaded Cubosomes for Enhancing Intranasal Drug Delivery: Development, Characterization, Ex Vivo Permeation, and Brain Biodistribution Studies

Verapamil hydrochloride (VRP), an antihypertensive calcium channel blocker drug has limited bioavailability and short half-life when taken orally. The present study was aimed at developing cubosomes containing VRP for enhancing its bioavailability and targeting to brain for cluster headache (CH) treatment as an off-label use. Factorial design was conducted to analyze the impact of different components on entrapment efficiency (EE%), particle size (PS), zeta potential (ZP), and percent drug release. Various in-vitro characterizations were performed followed by pharmacokinetic and brain targeting studies. The results revealed the significant impact of glyceryl monooleate (GMO) on increasing EE%, PS, and ZP of cubosomes with a negative influence on VRP release. The remarkable effect of Poloxamer 407 (P407) on decreasing EE%, PS, and ZP of cubosomes was observed besides its influence on accelerating VRP release%. The DSC thermograms indicated the successful entrapment of the amorphous state of VRP inside the cubosomes. The design suggested an optimized formulation containing GMO (50% w/w) and P407 (5.5% w/w). Such formulation showed a significant increase in drug permeation through nasal mucosa with high Er value (2.26) when compared to VRP solution. Also, the histopathological study revealed the safety of the utilized components used in the cubosomes preparation. There was a significant enhancement in the VRP bioavailability when loaded in cubosomes owing to its sustained release favored by its direct transport to brain. The I.N optimized formulation had greater BTE% and DTP% at 183.53% and 90.19%, respectively in comparison of 41.80% and 59% for the I.N VRP solution.

Vaccine adjuvants: current status, research and development, licensing, and future opportunities

Vaccines represent one of the most significant inventions in human history and have revolutionized global health. Generally, a vaccine functions by triggering the innate immune response and stimulating antigen-presenting cells, leading to a defensive adaptive immune response against a specific pathogen's antigen. As a key element, adjuvants are chemical materials often employed as additives to increase a vaccine's efficacy and immunogenicity. For over 90 years, adjuvants have been essential components in many human vaccines, improving their efficacy by enhancing, modulating, and prolonging the immune response. Here, we provide a timely and comprehensive review of the historical development and the current status of adjuvants, covering their classification, mechanisms of action, and roles in different vaccines. Additionally, we perform systematic analysis of the current licensing processes and highlights notable examples from clinical trials involving vaccine adjuvants. Looking ahead, we anticipate future trends in the field, including the development of new adjuvant formulations, the creation of innovative adjuvants, and their integration into the broader scope of systems vaccinology and vaccine delivery. The article posits that a deeper understanding of biochemistry, materials science, and vaccine immunology is crucial for advancing vaccine technology. Such advancements are expected to lead to the future development of more effective vaccines, capable of combating emerging infectious diseases and enhancing public health.

Oral peptide therapeutics for diabetes treatment: State-of-the-art and future perspectives

Diabetes, characterized by hyperglycemia, is a major cause of death and disability worldwide. Peptides, such as insulin and glucagon-like peptide-1 (GLP-1) analogs, have shown promise as treatments for diabetes due to their ability to mimic or enhance insulin's actions in the body. Compared to subcutaneous injection, oral administration of anti-diabetic peptides is a preferred approach. However, biological barriers significantly reduce the efficacy of oral peptide therapeutics. Recent advancements in drug delivery systems and formulation techniques have greatly improved the oral delivery of peptide therapeutics and their efficacy in treating diabetes. This review will highlight (1) the benefits of oral anti-diabetic peptide therapeutics; (2) the biological barriers for oral peptide delivery, including pH and enzyme degradation, intestinal mucosa barrier, and biodistribution barrier; (3) the delivery platforms to overcome these biological barriers. Additionally, the review will discuss the prospects in this field. The information provided in this review will serve as a valuable guide for future developments in oral anti-diabetic peptide therapeutics.

De novo development of small cyclic peptides that are orally bioavailable

Cyclic peptides can bind challenging disease targets with high affinity and specificity, offering enormous opportunities for addressing unmet medical needs. However, as with biological drugs, most cyclic peptides cannot be applied orally because they are rapidly digested and/or display low absorption in the gastrointestinal tract, hampering their development as therapeutics. In this study, we developed a combinatorial synthesis and screening approach based on sequential cyclization and one-pot peptide acylation and screening, with the possibility of simultaneously interrogating activity and permeability. In a proof of concept, we synthesized a library of 8,448 cyclic peptides and screened them against the disease target thrombin. Our workflow allowed multiple iterative cycles of library synthesis and yielded cyclic peptides with nanomolar affinities, high stabilities and an oral bioavailability (%F) as high as 18% in rats. This method for generating orally available peptides is general and provides a promising push toward unlocking the full potential of peptides as therapeutics.

A Comprehensive Analysis of Biopharmaceutical Products Listed in the FDA's Purple Book

Although biopharmaceuticals constitute around 10% of the drug landscape, eight of the ten top-selling products were biopharmaceuticals in 2023. This study did a comprehensive analysis of the FDA's Purple Book database. Firstly, our research uncovered market trends and provided insights into biologics distributions. According to the investigation, although biotechnology has advanced and legislative shifts have made the approval process faster, there are still challenges to overcome, such as molecular instability and formulation design. Moreover, our research comprehensively analyzed biological formulations, pointing out significant strategies regarding administration routes, dosage forms, product packaging, and excipients. In conjunction with biologics, the widespread integration of innovative delivery strategies will be implemented to confront the evolving challenges in healthcare and meet an expanding array of treatment needs.

Microneedle combined with iontophoresis and electroporation for assisted transdermal delivery of goniothalamus macrophyllus for enhancement sonophotodynamic activated cancer therapy

The underlying study was carried out aiming at transdermal drug delivery (TDD) of Goniothalamus macrophyllus as sono-photo-sensitizer (SPS) using microneedle (MN) arrays with iontophoresis (MN-IP), electroporation (MN-EP) in conjunction with applying photodynamic therapy (PDT), sonodynamic therapy (SDT) and sono-photodynamic therapy (SPDT) as an up-to-date activated cancer treatment modality. Study was conducted on 120 male Swiss Albino mice, inoculated with Ehrlich ascites carcinoma (EAC) divided into 9 groups. We employed three different arrays of MN electrodes were used (parallel, triangular, and circular), EP, IP with different volts (6, 9, 12 V), an infrared laser and an ultrasound (pulsed and continuous wave) as our two energy sources. Results revealed that parallel 6 V TDD@MN@IP@EP can be used as effective delivery system for G. macrophyllus from skin directly to target EAC cells. In addition MN@IP@EP@TDD G. macrophyllus is a potential SPS for SPDT treatment of EAC. With respect to normal control mice and as opposed to the EAC untreated control mice, MN@EP@IP TDD G. macrophyllus in the laser, ultrasound, and combination activated groups showed a significant increase in the antioxidant markers TAC level and the GST, GR, Catalase, and SOD activities, while decrease in lipid peroxidation oxidative stress parameter MDA levels. In addition significantly increased apoptotic genes expressions (p53, caspase (3, 9), Bax, and TNF alpha) and on the other hand decreased anti- apoptotic (Bcl-2) and angiogenic (VEGF) genes expressions. Moreover significantly ameliorate liver and kidney function decreasing ALT, AST, urea and creatinine respectively. Furthermore MN@IP@EP@TDD G. macrophyllus combined with SPDT was very effective at reducing the growth of tumors and even causing cell death according to microscopic H&E stain results. This process may be related to a sono- and/or photochemical activation mechanism. According to the findings, MN@IP@EP@TDD G. macrophyllus has a lot of potential as a novel, efficient delivery method that in combination with infrared laser and ultrasound activation SPDT demonstrated promising anticancer impact for treating cancer.

Personalized Cancer Nanomedicine: Overcoming Biological Barriers for Intracellular Delivery of Biopharmaceuticals

The success of personalized medicine in oncology relies on using highly effective and precise therapeutic modalities such as small interfering RNA (siRNA) and monoclonal antibodies (mAbs). Unfortunately, the clinical exploitation of these biological drugs has encountered obstacles in overcoming intricate biological barriers. Drug delivery technologies represent a plausible strategy to overcome such barriers, ultimately facilitating the access to intracellular domains. Here, an overview of the current landscape on how nanotechnology has dealt with protein corona phenomena as a first and determinant biological barrier is presented. This continues with the analysis of strategies facilitating access to the tumor, along with conceivable methods for enhanced tumor penetration. As a final step, the cellular barriers that nanocarriers must confront in order for their biological cargo to reach their target are deeply analyzed. This review concludes with a critical analysis and future perspectives of the translational advances in personalized oncological nanomedicine.

Challenging the Norm: A Multidisciplinary Perspective on Intravenous to Subcutaneous Bridging Strategies for Biologics

The transition from intravenous (i.v.) to subcutaneous (s.c.) administration of biologics is a critical strategy in drug development aimed at improving patient convenience, compliance, and therapeutic outcomes. Focusing on the increasing role of model-informed drug development (MIDD) in the acceleration of this transition, an in-depth overview of the essential clinical pharmacology, and regulatory considerations for successful i.v. to s.c. bridging for biologics after the i.v. formulation has been approved are presented. Considerations encompass multiple aspects beginning with adequate pharmacokinetic (PK) and pharmacodynamic (i.e., exposure-response) evaluations which play a vital role in establishing comparability between the i.v. and s.c. routes of administrations. Selected key recommendations and points to consider include: (i) PK characterization of the s.c. formulation, supported by the increasing preclinical understanding of the s.c. absorption, and robust PK study design and analyses in humans; (ii) a thorough characterization of the exposure-response profiles including important metrics of exposure for both efficacy and safety; (iii) comparability studies designed to meet regulatory considerations and support approval of the s.c. formulation, including noninferiority studies with PK and/or efficacy and safety as primary end points; and (iv) comprehensive safety package addressing assessments of immunogenicity and patients' safety profile with the new route of administration. Recommendations for successful bridging strategies are evolving and MIDD approaches have been used successfully to accelerate the transition to s.c. dosing, ultimately leading to improved patient experiences, adherence, and clinical outcomes.

Self-assembled peptide hydrogels for the treatment of diabetes and associated complications

Diabetes is a widespread epidemic that includes a number of comorbid conditions that greatly increase the chance of acquiring other chronic illnesses. Every year, there are significantly more people with diabetes because of the rise in type-2 diabetes prevalence. The primary causes of illness and mortality worldwide are, among these, hyperglycemia and its comorbidities. There has been a lot of interest in the creation of peptide-based hydrogels as a potentially effective platform for the treatment of diabetes and its consequences. Here, we emphasize the use of self-assembled hydrogel formulations and their unique potential for the treatment/management of type-2 diabetes and its consequences. (i.e., wounds). Key aspects covered include the characteristics of self-assembled peptide hydrogels, methods for their preparation, and their pre-clinical and clinical applications in addressing metabolic disorders such as type-2 diabetes.

Hydrogel-encapsulated medium chain lipid-modified zeolite imidazole framework-90 as a promising platform for oral delivery of proteins

The administration of protein therapeutics through oral means is seen as a convenient and painless experience for patients, making it a significant consideration in the field of drug delivery. Nevertheless, the challenging conditions within the gastrointestinal tract, along with the obstacles to absorption, impede the efficient transportation of proteins. Here, we successfully implemented post-synthetic modifications to attach medium-chain lipids (C10) onto the surface of zeolitic imidazole framework-90 (ZIF-90), then encapsulated the nanoparticles with sodium alginate, resulting in a potential platform for the oral administration of proteins. By means of biomimetic mineralization, ZIF-90 achieves a simple and efficient encapsulation of proteins of varying sizes, while shielding them against degradation by digestive enzymes. Sodium alginate hydrogel protects proteins against gastric acid and helps the cargo to rapidly penetrate the mucus layer. Through a mixed mechanism dominated by micropinocytosis, the C10-conjugated ZIF-90 (ZIF-90-C10) can be uptake by Caco-2 cells with a 200-400% increase and transported through the Golgi apparatus after escaping from lysosomes, exhibiting enhanced uptake in the overall gastrointestinal tract. Furthermore, ZIF-90-C10 retains its adenosine triphosphate-responsive release, which drastically lowers the likelihood of accumulation in vivo and allows targeted delivery for disease cells. Our work highlights mid-chain lipid conjugation as a potent approach to enhancing nanoparticle delivery efficiency and a potential strategy for oral delivery of biomacromolecules when combined with pH-responsive gels.

The Necessity to Investigate In Vivo Fate of Nanoparticle-Loaded Dissolving Microneedles

Transdermal drug delivery systems are rapidly gaining prominence and have found widespread application in the treatment of numerous diseases. However, they encounter the challenge of a low transdermal absorption rate. Microneedles can overcome the stratum corneum barrier to enhance the transdermal absorption rate. Among various types of microneedles, nanoparticle-loaded dissolving microneedles (DMNs) present a unique combination of advantages, leveraging the strengths of DMNs (high payload, good mechanical properties, and easy fabrication) and nanocarriers (satisfactory solubilization capacity and a controlled release profile). Consequently, they hold considerable clinical application potential in the precision medicine era. Despite this promise, no nanoparticle-loaded DMN products have been approved thus far. The lack of understanding regarding their in vivo fate represents a critical bottleneck impeding the clinical translation of relevant products. This review aims to elucidate the current research status of the in vivo fate of nanoparticle-loaded DMNs and elaborate the necessity to investigate the in vivo fate of nanoparticle-loaded DMNs from diverse aspects. Furthermore, it offers insights into potential entry points for research into the in vivo fate of nanoparticle-loaded DMNs, aiming to foster further advancements in this field.

Anti-thrombotic Effects Mediated by a Novel Dual-Target Peptide Inhibiting Both Platelet Aggregation and Thrombin Activity without Causing Bleeding

BACKGROUND

 Classical anticoagulants and antiplatelets are associated with high frequencies of bleeding complications or treatment failure when used as single agents. Thrombin plays an important role in the blood coagulation system. GP IIb/IIIa is the central receptor of platelets, which can recognize the Arg-Gly-Asp (RGD) sequence and activate platelets.

MATERIAL AND METHODS

 Molecular simulation and homology modeling were performed to design a novel dual-target anticoagulant short peptide (PTIP ). The activities of PTIP on coagulation and platelet in vitro were analyzed. The antithrombotic activity of PTIP was determined by pulmonary thromboembolism model, ferric chloride injury model and arteriovenous bypass thrombosis model. Bleeding effect and toxicity of PTIP were evaluated.

RESULTS

 We have constructed a novel dual-target peptide (PTIP) based on the direct thrombin inhibitor peptide (DTIP). PTIP was expressed at high levels in Pichia pastoris. PTIP interfered with thrombin-mediated coagulation and ADP-induced platelet aggregation in vitro. When injected intravenously or subcutaneously, PTIP showed potent and dose-dependent extension of aPTT and PT which were similar to DTIP; but only PTIP was capable of inhibiting platelet aggregation. PTIP (1.0 mg/kg) decelerated thrombosis formation in venous and arterial vessels induced by FeCl3 injury. PTIP (1.0 mg/kg) also prevented deep venous thrombosis and increased the survival rate associated with pulmonary thromboembolism. And PTIP effectively reduced thrombus length in arteriovenous bypass thrombosis model. Moreover, the antithrombotic dose of PTIP could not induce bleeding.

CONCLUSION

 These data establish that PTIP represents a novel antithrombotic agent whose effects involve both inhibition of platelet activation and reduction of fibrin generation. And PTIP not only can be used in venous thrombosis and arterial thrombosis, it can also replace the combined treatment of antiplatelet and anticoagulant drugs in thrombotic diseases.

Recent advances in oral insulin delivery technologies

With the rise in diabetes mellitus cases worldwide, oral delivery of insulin is preferred over subcutaneous insulin administration due to its good patient compliance and non-invasiveness, simplicity, and versatility. However, oral insulin delivery is hampered by various gastrointestinal barriers that result in low drug bioavailability and insufficient therapeutic efficiency. Numerous strategies have been developed to overcome these barriers and increase the bioavailability of oral insulin. Yet, no commercial oral insulin product is available to address all clinical hurdles because of various substantial obstacles related to the structural organization and physiological function of the gastrointestinal tract. Herein, we discussed the significant physiological barriers (including chemical, enzymatic, and physical barriers) that hinder the transportation and absorption of orally delivered insulin. Then, we showcased recent significant and innovative advances in oral insulin delivery technologies. Finally, we concluded the review with remarks on future perspectives on oral insulin delivery technologies and potential challenges for forthcoming clinical translation of oral insulin delivery technologies.

Cell-penetrating peptides for transmucosal delivery of proteins

Enabling non-invasive delivery of proteins across the mucosal barriers promises improved patient compliance and therapeutic efficacies. Cell-penetrating peptides (CPPs) are emerging as a promising and versatile tool to enhance protein and peptide permeation across various mucosal barriers. This review examines the structural and physicochemical attributes of the nasal, buccal, sublingual, and oral mucosa that hamper macromolecular delivery. Recent development of CPPs for overcoming those mucosal barriers for protein delivery is summarized and analyzed. Perspectives regarding current challenges and future research directions towards improving non-invasive transmucosal delivery of macromolecules for ultimate clinical translation are discussed.

Effects of Microenvironment and Dosing on Efficiency of Enhanced Cell Penetrating Peptide Nonviral Gene Delivery

Transfection, defined as functional delivery of cell-internalized nucleic acids, is dependent on many factors linked to formulation, vector, cell type, and microenvironmental culture conditions. We previously developed a technology termed glycosaminoglycan (GAG)-binding enhanced transduction (GET) to efficiently deliver a variety of cargoes intracellularly, using GAG-binding peptides and cell penetrating peptides (CPPs) in the form of nanoparticles, using conventional cell culture. Herein, we demonstrate that the most simple GET transfection formulation (employing the FLR peptide) is relatively poor at transfecting cells at increasingly lower dosages. However, with an endosomally escaping version (FLR:FLH peptide formulations) we demonstrate more effective transfection of cells with lower quantities of plasmid (p)DNA in vitro. We assessed the ability of single and serial delivery of our formulations to readily transfect cells and determined that temperature, pH, and atmospheric pressure can significantly affect transfected cell number and expression levels. Cytocompatible temperatures that maintain high cell metabolism (20-37 °C) were the optimal for transfection. Interestingly, serial delivery can maintain and enhance expression without viability being compromised, and alkaline pH conditions can aid overall efficiencies. Positive atmospheric pressures can also improve the transgene expression levels generated by GET transfection on a single-cell level. Novel nanotechnologies and gene therapeutics such as GET could be transformative for future regenerative medicine strategies. It will be important to understand how such approaches can be optimized at the formulation and application levels in order to achieve efficacy that will be competitive with viral strategies.

The Current and Promising Oral Delivery Methods for Protein- and Peptide-Based Drugs

Drugs based on peptides and proteins (PPs) have been widely used in medicine, beginning with insulin therapy in patients with diabetes mellitus over a century ago. Although the oral route of drug administration is the preferred one by the vast majority of patients and improves compliance, medications of this kind due to their specific chemical structure are typically delivered parenterally, which ensures optimal bioavailability. In order to overcome issues connected with oral absorption of PPs such as their instability depending on digestive enzymes and pH changes in the gastrointestinal (GI) system on the one hand, but also their limited permeability across physiological barriers (mucus and epithelium) on the other hand, scientists have been strenuously searching for novel delivery methods enabling peptide and protein drugs (PPDs) to be administered enterally. These include utilization of different nanoparticles, transport channels, substances enhancing permeation, chemical modifications, hydrogels, microneedles, microemulsion, proteolytic enzyme inhibitors, and cell-penetrating peptides, all of which are extensively discussed in this review. Furthermore, this article highlights oral PP therapeutics both previously used in therapy and currently available on the medical market.

Self-Assembled Skin-Penetrating Peptides with Controlled Supramolecular Properties for Enhanced Transdermal Delivery

The use of nanocarriers decorated with penetration-enhancing agents (PEAs) is considered to be a promising approach for efficient transdermal delivery. In this study, we developed short amphiphilic skin-penetrating peptides (17 amino acids) that functioned not only as PEAs but also as building blocks of nanocarriers without the incorporation of additional macromolecules for self-assembly and guest molecule encapsulation. Interestingly, varying only two amino acids in the hydrophobic moiety of the peptides resulted in significantly different self-assembly behavior, thermal stability, protease resistance, and skin-penetration efficiency in a human skin model. The analysis of the peptide secondary structure revealed that such characteristic changes arose due to the sequence variation-mediated conformational change in the hydrophobic block. These findings hold significant promise for the development of simple and effective delivery systems exhibiting controllable supramolecular properties.

Large volume subcutaneous delivery using multi-orifice jet injection

Needle-free jet injection is an alternative drug delivery technique that uses the liquid drug itself to penetrate through the skin. This technology is not only a promising alternative to hypodermic needles but also has the potential to replace intravenous delivery with rapid, needle-free subcutaneous delivery for large-volume treatments. In this work we propose a parallelised, 'multi-orifice' approach to overcome the volume constraints of subcutaneous tissue. We present a prototype multi-orifice nozzle with up to seven orifices and use this nozzle to perform injections into samples of ex vivo porcine tissue. These injections demonstrated the rapid (<0.15 s) delivery of up to 2 mL into the tissue using both three and seven orifices. Delivery success (measured as the percentage of fluid deposited in the tissue relative to the total volume that left the device) was very similar when using three versus seven injection orifices. A computational fluid dynamic model of multi-orifice jet injection is also presented. This model predicts that jet production is largely unaffected as the spacing between orifices is changed from 3 mm to 48 mm. This finding is supported by measurements of the speed, volume, and shape of the jets produced by the prototype nozzle that showed very similar jets were produced through all seven orifices. These findings demonstrate the feasibility of multi-orifice jet injection for needle-free delivery of large volumes. This promising technique has the potential to improve patient experience and reduce healthcare costs in large volume parenteral delivery applications.

Immune cell receptor-specific nanoparticles as a potent adjuvant for nasal split influenza vaccine delivery

Mucosal delivery systems have gained much attention as effective way for antigen delivery that induces both systemic and mucosal immunity. However, mucosal vaccination faces the challenges of mucus barrier and effective antigen uptake and presentation. In particular, split, subunit and recombinant protein vaccines that do not have an intact pathogen structure lack the efficiency to stimulate mucosal immunity. In this study, poly (lactic acid-co-glycolic acid-polyethylene glycol) (PLGA-PEG) block copolymers were modified by mannose to form a PLGA-PEG-Man conjugate (mannose modified PLGA-PEG), which were characterized. The novel nanoparticles (NPs) prepared with this material had a particle size of about 150 nm and a zeta potential of -15 mV, and possessed ideal mucus permeability, immune cell targeting, stability and low toxicity. Finally, PLGA-PEG-Man nanoparticles (PLGA-PEG-Man NPs) were successfully applied for intranasal delivery of split influenza vaccine in rat for the first time, which triggered strong systemic and mucosal immune responses. These studies suggest that PLGA-PEG-Man NPs could function as competitive potential nano-adjuvants to address the challenge of inefficient mucosal delivery of non-allopathogenic antigens.

Ultrasound Nanobubble Coupling Agent for Effective Noninvasive Deep-Layer Drug Delivery

Conventional coupling agents (such as polyvinylpyrrolidone, methylcellulose, and polyurethane) are unable to efficiently transport drugs through the skin's dual barriers (the epidermal cuticle barrier and the basement membrane barrier between the epidermis and dermis) when exposed to ultrasound, hindering deep and noninvasive transdermal drug delivery. In this study, nanobubbles prepared by the double emulsification method and aminated hyaluronic acid are crosslinked with aldehyde-based hyaluronic acid by dynamic covalent bonding through the Schiff base reaction to produce an innovative ultrasound-nanobubble coupling agent. By amplifying the cavitation effect of ultrasound, drugs can be efficiently transferred through the double barrier of the skin and delivered to deep layers. In an in vitro model of isolated porcine skin, this agent achieves an effective penetration depth of 728 µm with the parameters of ultrasound set at 2 W, 650 kHz, and 50% duty cycle for 20 min. Consequently, drugs can be efficiently delivered to deeper layers noninvasively. In summary, this ultrasound nanobubble coupling agent efficiently achieves deep-layer drug delivery by amplifying the ultrasonic cavitation effect and penetrating the double barriers, heralding a new era for noninvasive drug delivery platforms and disease treatment.

A comprehensive review of advanced nasal delivery: Specially insulin and calcitonin

Peptide drugs through nasal mucous membrane, such as insulin and calcitonin have been widely used in the medical field. There are always two sides to a coin. One side, intranasal drug delivery can imitate the secretion pattern in human body, having advantages of physiological structure and convenient use. Another side, the low permeability of nasal mucosa, protease environment and clearance effect of nasal cilia hinder the intranasal absorption of peptide drugs. Researchers have taken multiple means to achieve faster therapeutic concentration, lower management dose, and fewer side effects for better nasal preparations. To improve the peptide drugs absorption, various strategies had been explored via the nasal mucosa route. In this paper, we reviewed the achievements of 18 peptide drugs in the past decade about the perspectives of the efficacy, mechanism of enhancing intranasal absorption and safety. The most studies were insulin and calcitonin. As a result, absorption enhancers, nanoparticles (NPs) and bio-adhesive system are the most widely used. Among them, chitosan (CS), cell penetrating peptides (CPPs), tight junction modulators (TJMs), soft NPs and gel/hydrogel are the most promising strategies. Moreover, two or three strategies can be combined to prepare drug vectors. In addition, spray freeze dried (SFD), self-emulsifying nano-system (SEN), and intelligent glucose reaction drug delivery system are new research directions in the future.

Microfluidic encapsulation of enzymes and steroids within solid lipid nanoparticles

The production of solid lipid nanoparticles (SLNs) is challenging, especially when considering the incorporation of biologics. A novel in-house method of microfluidic production of biologic-encapsulated SLNs is proposed, using a variety of base materials for formulation to help overcome the barriers presented during manufacture and administration. Trypsin is used as a model drug for hydrophilic encapsulation whilst testosterone is employed as a positive non-biologic lipophilic control active pharmaceutical ingredient. Particle sizes obtained ranged from 160 to 320 nm, and a lead formulation has been identified from the combinations assayed, allowing for high encapsulation efficiencies (47-90%, respectively) of both the large hydrophilic and the small hydrophobic active pharmaceutical ingredients (APIs). Drug release profiles were analysed in vitro to provide useful insight into sustained kinetics, providing data towards future in vivo studies, which displayed a slow prolonged release for testosterone and a quicker burst release for trypsin. The study represents a large leap forward in the field of SLN production, especially in the field of difficult-to-encapsulate molecules, and the technique also benefits from being more environmentally sustainable due to the use of microfluidics.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

Insulin is recognized as a crucial weapon in managing diabetes. Subcutaneous (s.c.) injections are the traditional approach for insulin administration, which usually have many limitations. Numerous alternative (non-invasive) slants through different routes have been explored by the researchers for making needle-free delivery of insulin for attaining its augmented absorption as well as bioavailability. The current review delineating numerous pros and cons of several novel approaches of non-invasive insulin delivery by overcoming many of their hurdles. Primary information on the topic was gathered by searching scholarly articles from PubMed added with extraction of data from auxiliary manuscripts. Many approaches (discussed in the article) are meant for the delivery of a safe, effective, stable, and patient friendly administration of insulin via buccal, oral, inhalational, transdermal, intranasal, ocular, vaginal and rectal routes. Few of them have proven their clinical efficacy for maintaining the glycemic levels, whereas others are under the investigational pipe line. The developed products are comprising of many advanced micro/nano composite technologies and few of them might be entering into the market in near future, thereby garnishing the hopes of millions of diabetics who are under the network of s.c. insulin injections.

Overcoming Barriers Associated with Oral Delivery of Differently Sized Fluorescent Core-Shell Silica Nanoparticles

Oral delivery, while a highly desirable form of nanoparticle-drug administration, is limited by challenges associated with overcoming several biological barriers. Here, the authors study how fluorescent and poly(ethylene glycol)-coated (PEGylated) core-shell silica nanoparticles sized 5 to 50 nm interact with major barriers including intestinal mucus, intestinal epithelium, and stomach acid. From imaging fluorescence correlation spectroscopy studies using quasi-total internal reflection fluorescence microscopy, diffusion of nanoparticles through highly scattering mucus is progressively hindered above a critical hydrodynamic size around 20 nm. By studying Caco-2 cell monolayers mimicking the intestinal epithelia, it is observed that ultrasmall nanoparticles below 10 nm diameter (Cornell prime dots, [C' dots]) show permeabilities correlated with high absorption in humans from primarily enhanced passive passage through tight junctions. Particles above 20 nm diameter exclusively show active transport through cells. After establishing C' dot stability in artificial gastric juice, in vivo oral gavage experiments in mice demonstrate successful passage through the body followed by renal clearance without protein corona formation. Results suggest C' dots as viable candidates for oral administration to patients with a proven pathway towards clinical translation and may generate renewed interest in examining silica as a food additive and its effects on nutrition and health.

A Comprehensive Study on Nanoparticle Drug Delivery to the Brain: Application of Machine Learning Techniques

The delivery of drugs to specific target tissues and cells in the brain poses a significant challenge in brain therapeutics, primarily due to limited understanding of how nanoparticle (NP) properties influence drug biodistribution and off-target organ accumulation. This study addresses the limitations of previous research by using various predictive models based on collection of large data sets of 403 data points incorporating both numerical and categorical features. Machine learning techniques and comprehensive literature data analysis were used to develop models for predicting NP delivery to the brain. Furthermore, the physicochemical properties of loaded drugs and NPs were analyzed through a systematic analysis of pharmacodynamic parameters such as plasma area under the curve. The analysis employed various linear models, with a particular emphasis on linear mixed-effect models (LMEMs) that demonstrated exceptional accuracy. The model was validated via the preparation and administration of two distinct NP formulations via the intranasal and intravenous routes. Among the various modeling approaches, LMEMs exhibited superior performance in capturing underlying patterns. Factors such as the release rate and molecular weight had a negative impact on brain targeting. The model also suggests a slightly positive impact on brain targeting when the drug is a P-glycoprotein substrate.

Nasal delivery of polymeric nanoDisc mobilizes a synergy of central and peripheral amyloid-β clearance to treat Alzheimer's disease

The disequilibrium of amyloid β-peptide (Aβ) between the central and peripheral pools has been claimed as an initiating event in Alzheimer's disease (AD). In this study, we employ discoidal high-density lipoproteins (HDL-Disc) mimicking Aβ antibody for directional flux of Aβ from central to peripheral catabolism, with desirable safety and translation potential. Structurally, HDL-Disc assembly (polyDisc) is prepared with aid of chitosan derivative polymerization. After intranasal administration and response to slightly acidic nasal microenvironment, polyDisc depolymerizes into carrier-free HDL-Disc with chitosan derivatives that adhere to the mucosal layer to reversibly open tight junctions, helping HDL-Disc penetrate the olfactory pathway into brain. Thereafter, HDL-Disc captures Aβ into microglia for central clearance or ferries Aβ out of the brain for liver-mediated compensatory catabolism. For synergy therapy, intranasal administration of polyDisc can effectively reduce intracerebral Aβ burden by 97.3% and vascular Aβ burden by 73.5%, ameliorate neurologic damage, and rescue memory deficits in APPswe/PS1dE9 transgenic AD mice with improved safety, especially vascular safety. Collectively, this design provides a proof of concept for developing Aβ antibody mimics to mobilize a synergy of central and peripheral Aβ clearance for AD treatment.

Green Biologics: Harnessing the Power of Plants to Produce Pharmaceuticals

Plants are increasingly used for the production of high-quality biological molecules for use as pharmaceuticals and biomaterials in industry. Plants have proved that they can produce life-saving therapeutic proteins (Elelyso™-Gaucher's disease treatment, ZMapp™-anti-Ebola monoclonal antibodies, seasonal flu vaccine, Covifenz™-SARS-CoV-2 virus-like particle vaccine); however, some of these therapeutic proteins are difficult to bring to market, which leads to serious difficulties for the manufacturing companies. The closure of one of the leading companies in the sector (the Canadian biotech company Medicago Inc., producer of Covifenz) as a result of the withdrawal of investments from the parent company has led to the serious question: What is hindering the exploitation of plant-made biologics to improve health outcomes? Exploring the vast potential of plants as biological factories, this review provides an updated perspective on plant-derived biologics (PDB). A key focus is placed on the advancements in plant-based expression systems and highlighting cutting-edge technologies that streamline the production of complex protein-based biologics. The versatility of plant-derived biologics across diverse fields, such as human and animal health, industry, and agriculture, is emphasized. This review also meticulously examines regulatory considerations specific to plant-derived biologics, shedding light on the disparities faced compared to biologics produced in other systems.

Subcutaneous Administration of a Zwitterionic Chitosan-Based Hydrogel for Controlled Spatiotemporal Release of Monoclonal Antibodies

Subcutaneous (SC) administration of monoclonal antibodies (mAbs) is a proven strategy for improving therapeutic outcomes and patient compliance. The current FDA-/EMA-approved enzymatic approach, utilizing recombinant human hyaluronidase (rHuPH20) to enhance mAbs SC delivery, involves degrading the extracellular matrix's hyaluronate to increase tissue permeability. However, this method lacks tunable release properties, requiring individual optimization for each mAb. Seeking alternatives, physical polysaccharide hydrogels emerge as promising candidates due to their tunable physicochemical and biodegradability features. Unfortunately, none have demonstrated simultaneous biocompatibility, biodegradability, and controlled release properties for large proteins (≥150 kDa) after SC delivery in clinical settings. Here, a novel two-component hydrogel comprising chitosan and chitosan@DOTAGA is introduced that can be seamlessly mixed with sterile mAbs formulations initially designed for intravenous (IV) administration, repurposing them as novel tunable SC formulations. Validated in mice and nonhuman primates (NHPs) with various mAbs, including trastuzumab and rituximab, the hydrogel exhibited biodegradability and biocompatibility features. Pharmacokinetic studies in both species demonstrated tunable controlled release, surpassing the capabilities of rHuPH20, with comparable parameters to the rHuPH20+mAbs formulation. These findings signify the potential for rapid translation to human applications, opening avenues for the clinical development of this novel SC biosimilar formulation.

Evaluation of Truncated AUC as an Alternative Measure to Assess Pharmacokinetic Comparability in Bridging Biologic-Device Using Prefilled Syringes and Autoinjectors

Pharmacokinetic (PK) comparisons between therapeutic biologics have largely been based on the total area under the concentration-time curve (AUC) and the maximum concentration (Cmax ). For biologics with a long half-life, a PK comparability study may be long in duration and costly to conduct. The goal of this study was to evaluate whether a truncated AUC (tAUC) can be used to assess PK comparability when bridging prefilled syringe (PFS) and autoinjector (AI) treatment options for biologics with a long half-life. Fifteen biologics license applications (BLAs) were included to determine the concordance and geometric percent coefficient of variation (%CV) between tAUCs evaluated on days 7, 14, 21, and 28 and AUC evaluated to infinity (AUC0-inf ). Concordance is established if the tAUCs are comparable with AUC0-inf . Trial simulation was performed to examine the effect of the absorption rate constant (ka ) and sample size on the concordance of tAUCs. The tAUCs evaluated on day 14, 21, and 28 had 100% concordance with AUC0-inf for all 15 BLAs. The concordance of tAUC evaluated at day 7 was 87.5%. Based on the trial simulation, tAUC evaluated to day 28 post-dose can achieve high concordance (≥85%) for biologics exhibiting linear or nonlinear elimination with a ka of ≥0.1/day and with a sample size of 70 subjects per arm. tAUC appears to be a promising alternative PK measure, relative to AUC0-inf , for PK comparability assessments.

Nanomedicines to treat rare neurological disorders: The case of Krabbe disease

The brain remains one of the most challenging therapeutic targets due to the low and selective permeability of the blood-brain barrier and complex architecture of the brain tissue. Nanomedicines, despite their relatively large size compared to small molecules and nucleic acids, are being heavily investigated as vehicles to delivery therapeutics into the brain. Here we elaborate on how nanomedicines may be used to treat rare neurodevelopmental disorders, using Krabbe disease (globoid cell leukodystrophy) to frame the discussion. As a monogenetic disorder and lysosomal storage disease affecting the nervous system, the lessons learned from examining nanoparticle delivery to the brain in the context of Krabbe disease can have a broader impact on the treatment of various other neurodevelopmental and neurodegenerative disorders. In this review, we introduce the epidemiology and genetic basis of Krabbe disease, discuss current in vitro and in vivo models of the disease, as well as current therapeutic approaches either approved or at different stage of clinical developments. We then elaborate on challenges in particle delivery to the brain, with a specific emphasis on methods to transport nanomedicines across the blood-brain barrier. We highlight nanoparticles for delivering therapeutics for the treatment of lysosomal storage diseases, classified by the therapeutic payload, including gene therapy, enzyme replacement therapy, and small molecule delivery. Finally, we provide some useful hints on the design of nanomedicines for the treatment of rare neurological disorders.

Smartphone-based iontophoresis transdermal drug delivery system for cancer treatment

Cancer is a leading cause of the death worldwide. However, the conventional cancer therapy still suffers from several limitations, such as systemic side effects, poor efficacy, and patient compliance due to limited accessibility to the tumor site. To address these issues, the localized drug delivery system has emerged as a promising approach. In this study, we developed an iontophoresis-based transdermal drug delivery system (TDDS) controlled by a smartphone application for cancer treatment. Iontophoresis, a low-intensity electric current-based TDDS, enhances drug permeation across the skin to provide potential for localized drug delivery and minimize systemic side effects. The fundamental mechanism of our system was modeled using finite element analysis and its performance was corroborated through the flow-through skin permeation tests using a plastic-based microfluidic chip. The results of in vitro cell experiments and skin deposition tests successfully demonstrated that our smartphone-controlled iontophoresis system significantly enhanced the drug permeation for cancer treatment. Therefore, this hand-held smartphone-based iontophoresis TDDS could be a powerful tool for self-administrated anticancer drug delivery applications.

Smart chemistry for traceless release of anticancer therapeutics

In the design of delivery strategies for anticancer therapeutics, the controlled release of intact cargo at the destined tumor and metastasis locations is of particular importance. To this end, stimuli-responsive chemical linkers have been extensively investigated owing to their ability to respond to tumor-specific physiological stimuli, such as lowered pH, altered redox conditions, increased radical oxygen species and pathological enzymatic activities. To prevent premature action and off-target effects, anticancer therapeutics are chemically modified to be transiently inactivated, a strategy known as prodrug development. Prodrugs are reactivated upon stimuli-dependent release at the sites of interest. As most drugs and therapeutic proteins have the optimal activity when released from carriers in their native and original forms, traceless release mechanisms are increasingly investigated. In this review, we summarize the chemical toolkit for developing innovative traceless prodrug strategies for stimuli-responsive drug delivery and discuss the applications of these chemical modifications in anticancer treatment including cancer immunotherapy.

A pan-SARS-CoV-2-specific soluble angiotensin-converting enzyme 2-albumin fusion engineered for enhanced plasma half-life and needle-free mucosal delivery

Immunocompromised patients often fail to raise protective vaccine-induced immunity against the global emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Although monoclonal antibodies have been authorized for clinical use, most have lost their ability to potently neutralize the evolving Omicron subvariants. Thus, there is an urgent need for treatment strategies that can provide protection against these and emerging SARS-CoV-2 variants to prevent the development of severe coronavirus disease 2019. Here, we report on the design and characterization of a long-acting viral entry-blocking angiotensin-converting enzyme 2 (ACE2) dimeric fusion molecule. Specifically, a soluble truncated human dimeric ACE2 variant, engineered for improved binding to the receptor-binding domain of SARS-CoV-2, was fused with human albumin tailored for favorable engagement of the neonatal fragment crystallizable receptor (FcRn), which resulted in enhanced plasma half-life and allowed for needle-free transmucosal delivery upon nasal administration in human FcRn-expressing transgenic mice. Importantly, the dimeric ACE2-fused albumin demonstrated potent neutralization of SARS-CoV-2 immune escape variants.