Genetics
SLC2A3 is a Potential Factor for Head and Neck Squamous Cancer Development through Tumor Microenvironment Alteration
Tumor immunity has garnered increasing attention in cancer treatment and progression. However there is still a challenge in understanding the mechanisms of specific molecules affecting the clinical prognosis and tumor microenvironment (TME).
Here we applied the ESTIMATE algorithm to calculate the immune and stromal scores in 504 HNSC cases from TCGA. Patients were grouped according to the median value of the immune and stromal. Clinicopathological characteristics and differentially expressed genes (DEG) were analyzed. Subsequently LASSO COX regression survival analysis and clinicopathological characteristics were conducted. Subsequently SLC2A3 was determined as a predictive factor that high expression of SLC2A3 at the mRNA and protein levels predicted a worse clinical prognosis. GSEA25099 was utilized for external validation of immune infiltration while tissue PCR IHC and Western Blot were used to confirm the expression levels of SLC2A3.
A series of immune-infiltration analyses showed that SLC2A3 expression was negatively correlated with CD8+ T cells significantly affecting the survival prognosis of HNSC. In the GSEA analysis the high expression of SLC2A3 was mainly enriched for immune-related biological processes. Meanwhile high expression of SLC2A3 possessed higher TIDE scores and was also strongly positively correlated with a series of immune checkpoints affecting survival prognosis thus causing greater susceptibility to immune escape.
Conclusively SLC2A3 is a potential oncogene and factor of HNSC development notably by an altered state of the immune microenvironment immune-suppressive regulation and immune escape.
Significance of Ribonucleoside-diphosphate Reductase Subunit M2 in Lung Adenocarcinoma
The Ribonucleoside-diphosphate Reductase subunit M2 (RRM2) is known to be overexpressed in various cancers though its specific functional implications remain unclear. This aims to elucidate the role of RRM2 in the progression of Lung Adenocarcinoma (LUAD) by exploring its involvement and potential impact.
RRM2 data were sourced from multiple databases to assess its diagnostic and prognostic significance in LUAD. We evaluated the association between RRM2 expression and immune cell infiltration analyzed its function and explored the effects of modulating RRM2 expression on LUAD cell characteristics through laboratory experiments.
RRM2 was significantly upregulated in LUAD tissues and cells compared to normal counterparts (p < 0.05) with rare genetic alterations noted (approximately 2%). This overexpression clearly distinguished LUAD from normal tissue (area under the curve (AUC): 0.963 95% confidence intervals (CI): 0.946-0.981). Elevated RRM2 expression was significantly associated with adverse clinicopathological characteristics and poor prognosis in LUAD patients. Furthermore a positive association was observed between RRM2 expression and immune cell infiltration. Pathway analysis revealed a critical connection between RRM2 and the cell cycle signaling pathway within LUAD. Targeting RRM2 inhibition effectively suppressed LUAD cell proliferation migration and invasion while promoting apoptosis. This intervention also modified the expression of several crucial proteins including the downregulation of CDC25A CDC25C RAD1 Bcl-2 and PPM1D and the upregulation of TP53 and Bax (p < 0.05).
Our findings highlight the potential utility of RRM2 expression as a biomarker for diagnosing and predicting prognosis in LUAD shedding new light on the role of RRM2 in this malignancy.
Lipid-Based Nanocarriers for Targeted Gene Delivery in Lung Cancer Therapy: Exploring a Novel Therapeutic Paradigm
Lung cancer is a significant cause of cancer-related death worldwide. It can be broadly categorised into small-cell lung cancer (SCLC) and Non-small cell lung cancer (NSCLC). Surgical intervention radiation therapy and the administration of chemotherapeutic medications are among the current treatment modalities. However the application of chemotherapy may be limited in more advanced stages of metastasis due to the potential for adverse effects and a lack of cell selectivity. Although small-molecule anticancer treatments have demonstrated effectiveness they still face several challenges. The challenges at hand in this context comprise insufficient solubility in water limited bioavailability at specific sites adverse effects and the requirement for epidermal growth factor receptor inhibitors that are genetically tailored. Bio-macromolecular drugs including small interfering RNA (siRNA) and messenger RNA (mRNA) are susceptible to degradation when exposed to the bodily fluids of humans which can reduce stability and concentration. In this context nanoscale delivery technologies are utilised. These agents offer encouraging prospects for the preservation and regulation of pharmaceutical substances in addition to improving the solubility and stability of medications. Nanocarrier-based systems possess the notable advantage of facilitating accurate and sustained drug release as opposed to traditional systemic methodologies. The primary focus of scientific investigation has been to augment the therapeutic efficacy of nanoparticles composed of lipids. Numerous nanoscale drug delivery techniques have been implemented to treat various respiratory ailments such as lung cancer. These technologies have exhibited the potential to mitigate the limitations associated with conventional therapy. As an illustration applying nanocarriers may enhance the solubility of small-molecule anticancer drugs and prevent the degradation of bio-macromolecular drugs. Furthermore these devices can administer medications in a controlled and extended fashion thereby augmenting the therapeutic intervention's effectiveness and reducing adverse reactions. However despite these promising results challenges remain that must be addressed. Multiple factors necessitate consideration when contemplating the application of nanoparticles in medical interventions. To begin with the advancement of more efficient delivery methods is imperative. In addition a comprehensive investigation into the potential toxicity of nanoparticles is required. Finally additional research is needed to comprehend these treatments' enduring ramifications. Despite these challenges the field of nanomedicine demonstrates considerable promise in enhancing the therapy of lung cancer and other respiratory diseases.
Role of Non-coding RNAs on the Radiotherapy Sensitivity and Resistance in Cancer Cells
Radiotherapy (RT) is an integral part of treatment management in cancer patients. However one of the limitations of this treatment method is the resistance of cancer cells to radiotherapy. These restrictions necessitate the introduction of modalities for the radiosensitization of cancer cells. It has been shown that Noncoding RNAs (ncRNAs) along with modifiers can act as radiosensitivity and radioresistant regulators in a variety of cancers by affecting double strand break (DSB) wnt signaling glycolysis irradiation induced apoptosis ferroptosis and cell autophagy. This review will provide an overview of the latest research on the roles and regulatory mechanisms of ncRNA after RT in in vitro and preclinical researches.
Theranostic Potential of Bacteriophages against Oral Squamous Cell Carcinoma
Oral Squamous Cell Carcinoma (OSCC) is a widespread and challenging disease that accounts for 94% of cancers of the oral cavity worldwide. Bacteriophages (phages) have shown promise as a potential theranostic agent for the treatment of OSCC. It may offer advantages in overcoming the challenges of conventional methods. Modern high-throughput pyrosequencing techniques confirm the presence of specific bacterial strains associated with OSCC. Bio-panning and filamentous phages facilitate visualization of the peptide on surfaces and show high affinity in OSCC cells. The peptide has the potential to bind integrin (αvβ6) aid in diagnosis and inhibit the proliferation of OSCC cells. Mimotopes of tumor-associated antigens show cytotoxic and immune responses against cancer cells. Biomarker-based approaches such as transferrin enable early OSCC diagnosis. A modified temperate phage introduces CRISPR-Cas3 to target antimicrobial-resistant bacteria associated with OSCC. The research findings highlight the evolving field of phage diagnostics and therapy and represent a new avenue for non-invasive targeted approaches to the detection and treatment of OSCC. However extensive clinical research is required to validate the efficacy of phages in innovative cancer theranostic strategies.
Single-cell and Bulk Transcriptomic Analyses Reveal a Stemness and Circadian Rhythm Disturbance-related Signature Predicting Clinical Outcome and Immunotherapy Response in Hepatocellular Carcinoma
Investigating the impact of stemness-related circadian rhythm disruption (SCRD) on hepatocellular carcinoma (HCC) prognosis and its potential as a predictor for immunotherapy response.
Circadian disruption has been linked to tumor progression through its effect on the stemness of cancer cells.
Develop a novel signature for SCRD to accurately predict clinical outcomes and immune therapy response in patients with HCC.
The stemness degree of patients with HCC was assessed based on the stemness index (mRNAsi). The co-expression circadian genes significantly correlated with mRNAsi were identified and defined as stemness- and circadian-related genes (SCRGs). The SCRD scores of samples and cells were calculated based on the SCRGs. Differentially expressed genes with a prognostic value between distinct SCRD groups were identified in bulk and single-cell datasets to develop an SCRD signature.
A higher SCRD score indicates a worse patient survival rate. Analysis of the tumor microenvironment revealed a significant correlation between SCRD and infiltrating immune cells. Heterogeneous expression patterns functional states genomic variants and cell-cell interactions between two SCRD populations were revealed by transcriptomic genomic and interaction analyses. The robust SCRD signature for predicting immunotherapy response and prognosis in patients with HCC was developed and validated in multiple independent cohorts.
In summary distinct tumor immune microenvironment patterns were confirmed under SCRD in bulk and single-cell transcriptomic and SCRD signature associated with clinical outcomes and immunotherapy response was developed and validated in HCC.
Applications of L-Arginine in Pregnancy and Beyond: An Emerging Pharmacogenomic Approach
L-arginine is a semi-essential amino acid that plays a critical role in various physiological processes such as protein synthesis wound healing immune function and cardiovascular regulation. The use of L-arginine in pregnancy has been an emerging topic in the field of pharmacogenomics. L-arginine an amino acid plays a crucial role in the production of nitric oxide which is necessary for proper placental development and fetal growth. Studies have shown that L-arginine supplementation during pregnancy can have positive effects on fetal growth maternal blood pressure and the prevention of preeclampsia. This emerging pharmacogenomic approach involves using genetic information to personalize L-arginine dosages for pregnant women based on their specific genetic makeup. By doing so it may be possible to optimize the benefits of L-arginine supplementation during pregnancy and improve pregnancy outcomes. This paper emphasizes the potential applications of L-arginine in pregnancy and the use of pharmacogenomic approaches to enhance its effectiveness. Nonetheless the emerging pharmacogenomic approach to the application of L-arginine offers exciting prospects for the development of novel therapies for a wide range of diseases.
Development of Cell and Gene Therapies for Clinical Use in the US and EU: Summary of Regulatory Guidelines
Recent decades have seen advancements in the management and treatment of difficult- to-treat diseases such as cancer. A special class of therapeutics called cell and gene therapy has been introduced in the past 10 years. Cell and gene therapy products have strengthened the treatment options for life-threatening diseases with unmet clinical needs and also provided the possibility of a potential cure for the disease in some of the patients. Cell and gene therapy products are gaining recognition and the interest in clinical development of cell and gene therapy products is increasing. Moreover as the class of cell and gene therapy products is relatively new there is a limited regulatory experience in the development and the developers of the cell and gene therapy products can often be puzzled with an array of questions on regulations. The current review intends to provide a basic understanding of regulatory guidelines from the FDA and EMA that are applicable to cell and gene therapy products. Essentials such as which office is responsible for the evaluation of applications which regulatory class/pathway is appropriate for development and what are the quality nonclinical and clinical studies that are needed to support the application are discussed in the article. In addition a summary of regulatory designations and the post-approval requirements such as Risk Evaluation and Mitigation Strategies (REMS) and long-term follow-up is included in the article. Developers (referred to as ‘sponsors’ in this article) of cell and gene therapies can use the respective guidance documents and other specific review articles cited in this review for detailed information on the topics.
HCST Expression Distinguishes Immune-hot and Immune-cold Subtypes in Pancreatic Ductal Adenocarcinoma
Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent malignancy of the pancreas and the incidence of this disease is approximately equivalent to the mortality rate. Immunotherapy has made a remarkable breakthrough in numerous cancers while its efficacy in PDAC remains limited due to the immunosuppressive microenvironment. Immunotherapy efficacy is highly correlated with the abundance of immune cells particularly cytotoxic T cells. Therefore molecular classifier is needed to identify relatively hot tumors that may benefit from immunotherapy.
In this study we carried out a transcriptome analysis of 145 pancreatic tumors to define the underlying immune regulatory mechanism driving the PDAC immunosuppressive microenvironment. The immune subtype was identified by consensus clustering and the underlying PDAC immune activation mechanism was thoroughly examined using single sample gene set enrichment analysis (ssGSEA). Area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to assess the accuracy of the molecular classifier in differentiating immunological subgroups of PDAC.5
The protein level of molecular classifier was verified by immunohistochemistry in human PDAC tissue. Immune-hot tumors displayed higher levels of immune cell infiltration and immune checkpoint in line with enriched immune escape pathways. Hematopoietic cell signal transducer (HCST) a molecular classifier used to differentiate immunological subtypes of PDAC has shown a substantial link with the expression levels of cytotoxic markers such as CD8A and CD8B. At the single cell level we found that HCST was predominantly expressed in CD8T cells. By immunohistochemistry and survival analysis we further demonstrated the prognostic value of HCST in PDAC.
We identified HCST as a molecular classifier to distinguish PDAC immune subtypes which may be useful for early diagnosis and targeted therapy of PDAC.
Efficacy and Safety of Pembrolizumab Monotherapy or Combined Therapy in Patients with Metastatic Triple-negative Breast Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Metastatic Triple-negative Breast Cancer (mTNBC) is the most aggressive form of breast cancer with a greater risk of metastasis and recurrence. Research studies have published in-depth analyses of the advantages and disadvantages of pembrolizumab and early data from numerous trials suggests that patients with mTNBC have had remarkable outcomes. This meta-analysis compares the data from numerous relevant studies in order to evaluate the safety and efficacy of pembrolizumab monotherapy or combination therapies for mTNBC.
To identify eligible RCTs a thorough literature search was carried out using electronic databases. CMA software was utilized to perform heterogeneity tests using fixed and random-effects models.
According to our pooled data the median Progression-free Survival (PFS) was 2.66 months and the median overall survival (OS) was 12.26 months. Furthermore by comparing efficacy indicators between PD-L1–positive and PD-L1–negative groups a correlation was found between the overexpression of PD-L1 with OS PFS and ORR. Patients with PD-L1-positive tumors had a higher response rate with an ORR of 21.1% compared to the patients with PD-L1-negative tumors. The ORR for first-line immunotherapy was higher than that of ≥second-line immunotherapy. In addition pembrolizumab plus combination treatment resulted in a pooled incidence of immune-related adverse events of 22.7%.
A modest response to pembrolizumab monotherapy was detected in the mTNBC patients. Furthermore a better outcome from pembrolizumab treatment may be predicted by PD-L1-positive status non-liver/lung metastases combination therapy and first-line immunotherapy. Pembrolizumab in combination with chemotherapy may be more beneficial for patients whose tumors are PD-L1 positive.
Evolution of Prime Editing Systems: Move Forward to the Treatment of Hereditary Diseases
The development of gene therapy using genome editing tools recently became relevant. With the invention of programmable nucleases it became possible to treat hereditary diseases due to introducing targeted double strand break in the genome followed by homology directed repair (HDR) or non-homologous end-joining (NHEJ) reparation. CRISPR-Cas9 is more efficient and easier to use in comparison with other programmable nucleases. To improve the efficiency and safety of this gene editing tool various modifications CRISPR-Cas9 basis were created in recent years such as prime editing – in this system Cas9 nickase is fused with reverse transcriptase and guide RNA which contains a desired correction. Prime editing demonstrates equal or higher correction efficiency as HDR-mediated editing and much less off-target effect due to inducing nick. There are several studies in which prime editing is used to correct mutations in which researchers reported little or no evidence of off-target effects. The system can also be used to functionally characterize disease variants. However prime editing still has several limitations that could be further improved. The effectiveness of the method is not yet high enough to apply it in clinical trials. Delivery of prime editors is also a big challenge due to their size. In the present article we observe the development of the platform and discuss the candidate proteins for efficiency enhancing main delivery methods and current applications of prime editing.
Gene Therapy for Skin Aging
Extrinsic and intrinsic factors contribute to skin aging; nonetheless they are intertwined. Moreover intrinsic skin aging mirrors age-related declines in the entire human body's internal organs. There is evidence that skin appearance is an indicator of the general health of somebody or a visual certificate of health. Earlier it was apparent that the intrinsic factors are unalterable but the sparkling of skin aging gene therapy on the horizon is changing this narrative. Skin aging gene therapy offers tools for skin rejuvenation natural beauty restoration and therapy for diseases affecting the entire skin. However skin aging gene therapy is an arduous and sophisticated task relying on precise interim stimulation of telomerase to extend telomeres and wend back the biological clock in the hopes to find the fountain of youth while preserving cells innate biological features. Finding the hidden fountain of youth will be a remarkable discovery for promoting aesthetics medicine genecosmetics and healthy aging. Caloric restriction offers ultimate health benefits and a reproducible way to promote longevity in mammals while delaying age-related diseases. Moreover exercise further enhances these health benefits. This article highlights the potential of skin aging gene therapy and foretells the emerging dawn of the genecosmetics era.
Advancements in CRISPR-Based Therapies for Genetic Modulation in Neurodegenerative Disorders
Neurodegenerative disorders pose significant challenges in the realm of healthcare as these conditions manifest in complex multifaceted ways often attributed to genetic anomalies. With the emergence of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology a new frontier has been unveiled in the quest for targeted precise genetic manipulation. This abstract explores the recent advancements and potential applications of CRISPR-based therapies in addressing genetic components contributing to various neurodegenerative disorders. The review delves into the foundational principles of CRISPR technology highlighting its unparalleled ability to edit genetic sequences with unprecedented precision. In addition it talks about the latest progress in using CRISPR to target specific genetic mutations linked to neurodegenerative diseases like Huntington's disease Alzheimer's disease amyotrophic lateral sclerosis (ALS) and Parkinson's disease. It talks about the most important studies and trials that show how well and safely CRISPR-based therapies work. This shows how this technology can change genetic variants that cause diseases. Notably the discussion emphasizes the challenges and ethical considerations associated with the implementation of CRISPR in clinical settings including off-target effects delivery methods and long-term implications. Furthermore the article explores the prospects and potential hurdles in the widespread application of CRISPR technology for treating neurodegenerative disorders. It touches upon the need for continued research improved delivery mechanisms and ethical frameworks to ensure responsible and equitable access to these groundbreaking therapies.
miR-124 in Neuroblastoma: Mechanistic Insights, Biomarker Potential, and Therapeutic Prospects
Neuroblastoma a malignancy predominantly affecting young children originates from neural crest cells in the sympathetic nervous system. It primarily appears in the adrenal gland but can also affect nerve tissues in regions such as the chest neck abdomen and pelvis. Despite advancements in treatment high-risk neuroblastoma patients often face poor prognoses underscoring the need for ongoing research. This review paper examines the numerous factors responsible for neuroblastoma emphasizing the importance of approaching the disorder with more strategic therapeutic methods. MicroRNAs particularly miR-124 play critical roles in gene regulation and cancer pathogenesis. Abundant in the brain miR-124 functions as a tumor suppressor by inhibiting cell growth migration and invasion and is often dysregulated in neuroblastoma. This study investigates the molecular functions of miR-124 in neuroblastoma its potential as a biomarker and its application in targeted therapy. MiR-124 regulates key pathways in neuroblastoma including PI3K/AKT TGF-β and p53 signaling impacting cell proliferation apoptosis and metastasis. The study also explores the promise of miR-124 as a biomarker for neuroblastoma through liquid biopsy enabling non-invasive diagnosis and disease monitoring. Therapeutic strategies targeting miR-124 pathways show potential for overcoming chemotherapy resistance and improving treatment efficacy. The research underscores the significance of miR-124 in neuroblastoma aiming to enhance early diagnosis identify specific drug targets and expand treatment options ultimately improving patient outcomes.
Molecular Docking, Pharmacophore Mapping, and Virtual Screening of Novel Glucokinase Activators as Antidiabetic Agents
A pivotal impetus has led to the development of numerous small molecules to develop therapeutic strategies for type 2 diabetes. Novel heterocyclic derivatives are now available with expansive pharmacological activity designed specifically to activate Glucokinase (GK) in the body. This target is of particular significance in antidiabetic drug design since it is a newly validated target. Individuals with type 2 diabetes are unable to maintain blood glucose homeostasis due to impaired glucokinase function. The novel approach to managing type 2 diabetes relies on utilizing heterocyclic derivatives to activate the GK enzyme also known as a metabolic enzyme.
In this research endeavor the primary objective was to improve drug delivery while minimizing adverse effects by using molecules that activate glucokinase.
There are 53000 compounds included in Maybridge's online repository which has been subjected to rigorous scrutiny. Eight two compounds that encompass the specific oxadiazole core were selectively extracted from this extensive collection. ChemBioDraw Ultra was used for structural drawing and AutoDock Vina 1.5.6 was used to perform docking analysis. For the online prediction of log P the SwissADME algorithm was employed. A PKCSM software program was used to predict toxicity for leading compounds.
Among all of the compounds AD80 and AD27 displayed the highest affinity for GK receptors. These compounds by adhering to Lipinski’s Rule of Five exhibited good absorption and excretion profiles through the gastrointestinal (GI) tract. Lipinski’s Rule of Five refers to physicochemical properties that favor good oral bioavailability and these specifications are zero to five hydrogen bond donors zero to ten hydrogen bond acceptors molecular weight below 500 and log P no more than five. These criteria ensure that the compounds of the invention have acceptable solubility and permeability which are vital prerequisites when given orally to be absorbed via the gastrointestinal wall metabolized and found in the urine. Therefore the chance of drug candidates exhibiting favorable pharmacokinetic characteristics is increased enhancing their chances of being developed for oral administration. In comparison with standard drugs Dorzagliatin as a glucokinase activator (GKA) and MRK (co-crystallized ligand) these compounds exhibit no skin sensitization AMES toxicity or hepatotoxicity.
The recently designed lead molecules exhibit an improved pharmacokinetic profile enhanced binding affinity and minimal toxicity based on the computational study potentially making them suitable candidates for further optimization as glucokinase activators.
Development of Novel Women's Friendly Antifungal Microemulsion Loaded Gel for Vulvovaginal Infections
The research was carried out to develop the microemulsion-loaded gel of curcumin alkylpolyglucoside and tea tree oil to treat vulvovaginal candidiasis infection.
Screening of oils surfactants and co-surfactants was done based on solubility studies and the construction of pseudo-ternary phase diagrams with curcumin. The microemulsion was characterized for globule size zeta potential viscosity and thermodynamic stability. Ex-vivo studies were carried out using Franz diffusion cells. The antifungal activity of microemulsion-loaded hydrogel was evaluated using the cup plate method using Candida albicans ATCC 10231 in glucose yeast agar medium.
The selected micro-emulsion consisted of curcumin 35µg/mL IPM+TTO (1:1) 0.1 mL Milcoside 100 + Acconon MC 8-2 EP NF 0.6-0.3 mL phosphate buffer pH 4 160 mL showed maximum thermodynamic stability and exhibited lowest particle size and highest intensity. The viscosity of microemulsion-loaded gel was 11.2 pa.s. The surface tension of the microemulsion was measured by tensiometer and was found to be 26.07 mN/m. Antimicrobial susceptibility testing assay was done according to NCCLs assay protocol and the EC50 value of our formulation was found to be 0.4465 μg/mL. In-vitro drug release and ex-vivo permeation studies showed 67.9% release in 420 minutes and 83.02% release in 360 minutes respectively. An in-vitro irritation study concluded that there was no redness or irritation on goat mucosa.
The texture analysis test showed adhesiveness at -172.46 g s at - 4.60 adhesive force and the peak load was 13.40 g. The microemulsion-loaded gel formulation can be a promising alternative to the marketed formulations available for vaginal yeast infections.
Advances in Research on Adropin: Potential Implications for Clinical Diagnosis and Possible Treatment – A Mini-Review
Adropin is 76-amino acids protein. It was discovered in 2008. Adropin expression was found in the liver brain heart kidneys pancreas testis and ovary umbilical vein coronary artery endothelial cells aortic smooth muscle cells and monocytes/macrophages. Adropin is involved in energy balance and it has an endothelial protective effect. Changes in adropin content have been found in many diseases and disorders such as obesity diabetes mellitus type 1 and 2 coronary artery disease myocardial infarction rheumatoid arthritis primary Sjögren's syndrome multiple sclerosis nonalcoholic fatty liver disease polycystic ovary syndrome and preeclampsia. This mini-review focuses on those papers that have potential implications for clinical diagnosis or possible treatment. It can be assumed that adropin can be useful in the diagnosis of certain diseases. It seems to be a promising candidate for the treatment of diabetes atherosclerosis polycystic ovary syndrome and diseases of the nervous system associated with cognitive decline.
Plasma Protein Adsorption on Melphalan Prodrug Bearing Liposomes - Bare, Stealth, and Targeted
Plasma protein binding is inevitable for nanomaterials injected into blood circulation. For liposomes this process is affected by the lipid composition of the bilayer. Membrane constituents and their ratio define liposome characteristics namely surface charge and hydrophobicity which drive protein adsorption. Roughly 30 years ago the correlation between the amount of bound proteins and the resulting circulation time of liposomes was established by S. Semple A. Chonn and P. Cullis. Here we have estimated ex vivo plasma protein binding primarily to determine the impact of melphalan prodrug inclusion into bilayer on bare PEGylated (stealth) and Sialyl Lewis X (SiaLeX)-decorated liposomes.
Liposomes were allowed to bind plasma proteins for 15 minutes then liposome-protein complexes were isolated and protein and lipid quantities were assessed in the complexes. In addition the uptake by activated HUVEC cells was evaluated for SiaLeX-decorated liposomes.
Melphalan moieties on the bilayer surface enrich protein adsorption compared to pure phosphatidylcholine sample. Although PEG-lipid had facilitated a significant decrease in protein adsorption in the control sample when prodrug was added to the composition the degree of protein binding was restored to the level of melphalan liposomes without a stealth barrier. A similar effect was observed for SiaLeX-decorated liposomes.
None of the compositions reported here should suffer from quick elimination from circulation according to the cut-off values introduced by Cullis and colleagues. Nevertheless the amount of bound proteins is sufficient to affect biodistribution namely to impair receptor recognition of SiaLeX and reduce liposome uptake by endothelial cells.