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1.
Clin Transl Sci ; 17(6): e13800, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38818903

ABSTRACT

Pharmacogenetic (PGx)-informed medication prescription is a cutting-edge genomic application in contemporary medicine, offering the potential to overcome the conventional "trial-and-error" approach in drug prescription. The ability to use an individual's genetic profile to predict drug responses allows for personalized drug and dosage selection, thereby enhancing the safety and efficacy of treatments. However, despite significant scientific and clinical advancements in PGx, its integration into routine healthcare practices remains limited. To address this gap, the Qatar Genome Program (QGP) has embarked on an ambitious initiative known as QPGx-CARES (Qatar Pharmacogenetics Clinical Applications and Research Enhancement Strategies), which aims to set a roadmap for optimizing PGx research and clinical implementation on a national scale. The goal of QPGx-CARES initiative is to integrate PGx testing into clinical settings with the aim of improving patient health outcomes. In 2022, QGP initiated several implementation projects in various clinical settings. These projects aimed to evaluate the clinical utility of PGx testing, gather valuable insights into the effective dissemination of PGx data to healthcare professionals and patients, and identify the gaps and the challenges for wider adoption. QPGx-CARES strategy aimed to integrate evidence-based PGx findings into clinical practice, focusing on implementing PGx testing for cardiovascular medications, supported by robust scientific evidence. The current initiative sets a precedent for the nationwide implementation of precision medicine across diverse clinical domains.


Subject(s)
Pharmacogenetics , Precision Medicine , Humans , Qatar , Pharmacogenetics/methods , Precision Medicine/methods , Pharmacogenomic Testing
2.
Nat Prod Res ; 37(4): 542-550, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35491702

ABSTRACT

Soft corals distributed across the Red Sea coasts are a rich source of diverse and bioactive natural products. Chemical probing of the Red Sea soft coral Litophyton arboreum led to isolation and structural characterization of an undescribed sesquiterpenoid, litoarbolide A (1), along with 14 previously reported metabolites (2-15). The chemical structures of the isolates were assigned based on NMR as well as high resolution electrospray ionization mass spectrometry (HR-ESI-MS) data. Litoarbolide A is supposed to be the biosynthetic precursor to other sesquiterpenoids, which formed via further post-translational modifications. Furthermore, these metabolites were evaluated for anti-malarial activity, where only the acyclic sesquiterpenoid of a sec-germacrane nucleus (7) showed an activity against chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 at 3.7 and 2.2 mg/mL, respectively. Moreover, the isolated metabolites were all non-toxic to the Vero cell line. These findings support the consideration of L. arboreum in further natural anti-malarial studies.


Subject(s)
Anthozoa , Antimalarials , Sesquiterpenes , Animals , Antimalarials/pharmacology , Anthozoa/chemistry , Indian Ocean , Chloroquine/pharmacology , Sesquiterpenes/pharmacology , Plasmodium falciparum
3.
Med ; 3(12): 813-814, 2022 12 09.
Article in English | MEDLINE | ID: mdl-36495859

ABSTRACT

To understand disease, scientists are producing comprehensive omics datasets. However, the majority of these are Eurocentric. Recently, the inclusion of patients from Asia and the Middle East in genomic analyses uncovered unique loci linked to COVID-19 severity. This demonstrates that focusing on diversity and underrepresented populations can benefit all.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Genomics , Bias , Asia , Middle East
4.
Nat Genet ; 54(12): 1761-1763, 2022 12.
Article in English | MEDLINE | ID: mdl-36446885
5.
Hum Mutat ; 43(4): 499-510, 2022 04.
Article in English | MEDLINE | ID: mdl-35112413

ABSTRACT

Despite recent biomedical breakthroughs and large genomic studies growing momentum, the Middle Eastern population, home to over 400 million people, is underrepresented in the human genome variation databases. Here we describe insights from Phase 1 of the Qatar Genome Program with whole genome sequenced 6047 individuals from Qatar. We identified more than 88 million variants of which 24 million are novel and 23 million are singletons. Consistent with the high consanguinity and founder effects in the region, we found that several rare deleterious variants were more common in the Qatari population while others seem to provide protection against diseases and have shaped the genetic architecture of adaptive phenotypes. These results highlight the value of our data as a resource to advance genetic studies in the Arab and neighboring Middle Eastern populations and will significantly boost the current efforts to improve our understanding of global patterns of human variations, human history, and genetic contributions to health and diseases in diverse populations.


Subject(s)
Genome, Human , Genomics , Consanguinity , Genetics, Population , Genome, Human/genetics , Genomics/methods , Humans , Middle East , Qatar/epidemiology
6.
NPJ Genom Med ; 7(1): 3, 2022 Jan 19.
Article in English | MEDLINE | ID: mdl-35046417

ABSTRACT

Risk genes for Mendelian (single-gene) disorders (SGDs) are consistent across populations, but pathogenic risk variants that cause SGDs are typically population-private. The goal was to develop "QChip1," an inexpensive genotyping microarray to comprehensively screen newborns, couples, and patients for SGD risk variants in Qatar, a small nation on the Arabian Peninsula with a high degree of consanguinity. Over 108 variants in 8445 Qatari were identified for inclusion in a genotyping array containing 165,695 probes for 83,542 known and potentially pathogenic variants in 3438 SGDs. QChip1 had a concordance with whole-genome sequencing of 99.1%. Testing of QChip1 with 2707 Qatari genomes identified 32,674 risk variants, an average of 134 pathogenic alleles per Qatari genome. The most common pathogenic variants were those causing homocystinuria (1.12% risk allele frequency), and Stargardt disease (2.07%). The majority (85%) of Qatari SGD pathogenic variants were not present in Western populations such as European American, South Asian American, and African American in New York City and European and Afro-Caribbean in Puerto Rico; and only 50% were observed in a broad collection of data across the Greater Middle East including Kuwait, Iran, and United Arab Emirates. This study demonstrates the feasibility of developing accurate screening tools to identify SGD risk variants in understudied populations, and the need for ancestry-specific SGD screening tools.

7.
Nat Prod Res ; 36(7): 1842-1850, 2022 Apr.
Article in English | MEDLINE | ID: mdl-32945198

ABSTRACT

Four undescribed cembranoids, sarcoroseolides A-D (1-4) along with nine reported related cembranoids (5-13) were isolated from the soft coral Sarcophyton roseum. The chemical structures of sarcoroseolides A-D were elucidated by extensive 1 D and 2 D NMR as well as HR-ESIMS spectroscopic data. Moreover, the geometric and absolute configurations were assigned by the modified Mosher's method and/or NOESY experiments. The extract and the isolated metabolites were evaluated for their potential anti-inflammatory and cytotoxic activities.


Subject(s)
Anthozoa , Diterpenes , Animals , Anthozoa/chemistry , Diterpenes/chemistry , Diterpenes/pharmacology , Indian Ocean , Magnetic Resonance Spectroscopy , Molecular Structure
8.
Cell Genom ; 2(10): 100192, 2022 Oct 12.
Article in English | MEDLINE | ID: mdl-36777996

ABSTRACT

Biobanks facilitate genome-wide association studies (GWASs), which have mapped genomic loci across a range of human diseases and traits. However, most biobanks are primarily composed of individuals of European ancestry. We introduce the Global Biobank Meta-analysis Initiative (GBMI)-a collaborative network of 23 biobanks from 4 continents representing more than 2.2 million consented individuals with genetic data linked to electronic health records. GBMI meta-analyzes summary statistics from GWASs generated using harmonized genotypes and phenotypes from member biobanks for 14 exemplar diseases and endpoints. This strategy validates that GWASs conducted in diverse biobanks can be integrated despite heterogeneity in case definitions, recruitment strategies, and baseline characteristics. This collaborative effort improves GWAS power for diseases, benefits understudied diseases, and improves risk prediction while also enabling the nomination of disease genes and drug candidates by incorporating gene and protein expression data and providing insight into the underlying biology of human diseases and traits.

9.
Front Cell Infect Microbiol ; 11: 768883, 2021.
Article in English | MEDLINE | ID: mdl-34869069

ABSTRACT

Qatar, a country with a strong health system and a diverse population consisting mainly of expatriate residents, has experienced two large waves of COVID-19 outbreak. In this study, we report on 2634 SARS-CoV-2 whole-genome sequences from infected patients in Qatar between March-2020 and March-2021, representing 1.5% of all positive cases in this period. Despite the restrictions on international travel, the viruses sampled from the populace of Qatar mirrored nearly the entire global population's genomic diversity with nine predominant viral lineages that were sustained by local transmission chains and the emergence of mutations that are likely to have originated in Qatar. We reported an increased number of mutations and deletions in B.1.1.7 and B.1.351 lineages in a short period. These findings raise the imperative need to continue the ongoing genomic surveillance that has been an integral part of the national response to monitor the SARS-CoV-2 profile and re-emergence in Qatar.


Subject(s)
COVID-19 , SARS-CoV-2 , Disease Outbreaks , Genomics , Humans , Qatar/epidemiology
10.
Genes (Basel) ; 12(11)2021 11 22.
Article in English | MEDLINE | ID: mdl-34828448

ABSTRACT

Host genomic information, specifically genomic variations, may characterize susceptibility to disease and identify people with a higher risk of harm, leading to better targeting of care and vaccination. Italy was the epicentre for the spread of COVID-19 in Europe, the first country to go into a national lockdown and has one of the highest COVID-19 associated mortality rates. Qatar, on the other hand has a very low mortality rate. In this study, we compared whole-genome sequencing data of 14398 adults and Qatari-national to 925 Italian individuals. We also included in the comparison whole-exome sequence data from 189 Italian laboratory-confirmed COVID-19 cases. We focused our study on a curated list of 3619 candidate genes involved in innate immunity and host-pathogen interaction. Two population-gene metric scores, the Delta Singleton-Cohort variant score (DSC) and Sum Singleton-Cohort variant score (SSC), were applied to estimate the presence of selective constraints in the Qatari population and in the Italian cohorts. Results based on DSC and SSC metrics demonstrated a different selective pressure on three genes (MUC5AC, ABCA7, FLNA) between Qatari and Italian populations. This study highlighted the genetic differences between Qatari and Italian populations and identified a subset of genes involved in innate immunity and host-pathogen interaction.


Subject(s)
COVID-19/genetics , Genetic Predisposition to Disease/genetics , Host Microbial Interactions/genetics , Adult , Alleles , COVID-19/epidemiology , Communicable Disease Control , Disease Susceptibility/metabolism , Exome/genetics , Female , Gene Frequency/genetics , Genetic Predisposition to Disease/epidemiology , Genetics, Population , Genomics/methods , Humans , Immunity, Innate/immunology , Italy/epidemiology , Male , Qatar/epidemiology , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Exome Sequencing/methods , Whole Genome Sequencing/methods
11.
J Clin Invest ; 131(14)2021 07 15.
Article in English | MEDLINE | ID: mdl-34043590

ABSTRACT

A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,864 COVID-19 cases (713 with severe and 1,151 with mild disease) and 15,033 ancestry-matched population controls across 4 independent COVID-19 biobanks. We tested whether rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only 1 rare pLOF mutation across these genes among 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We found no evidence of association of rare LOF variants in the 13 candidate genes with severe COVID-19 outcomes.


Subject(s)
COVID-19/genetics , COVID-19/immunology , Interferon Type I/genetics , Interferon Type I/immunology , Loss of Function Mutation , SARS-CoV-2 , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Child , Child, Preschool , Cohort Studies , Female , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Infant , Infant, Newborn , Interferon Regulatory Factor-7/genetics , Male , Middle Aged , Severity of Illness Index , Toll-Like Receptor 3/genetics , Exome Sequencing , Whole Genome Sequencing , Young Adult
12.
Life Sci Soc Policy ; 16(1): 12, 2020 Nov 01.
Article in English | MEDLINE | ID: mdl-33129349

ABSTRACT

In 2016, the World Innovation Summit for Health (WISH) published its Forum Report on precision medicine "PRECISION MEDICINE - A GLOBAL ACTION PLAN FOR IMPACT". Healthcare is undergoing a transformation, and it is imperative to leverage new technologies to generate new data and support the advent of precision medicine (PM). Recent scientific breakthroughs and technological advancements have improved our disease knowledge and altered diagnosis and treatment approaches resulting in a more precise, predictive, preventative and personalized health care that is customized for the individual patient. Consequently, the big data revolution has provided an opportunity to apply artificial intelligence and machine learning algorithms to mine such a vast data set. Additionally, personalized medicine promises to revolutionize healthcare, with its key goal of providing the right treatment to the right patient at the right time and dose, and thus the potential of improving quality of life and helping to bring down healthcare costs.This policy briefing will look in detail at the issues surrounding continued development, sustained investment, risk factors, testing and approval of innovations for better strategy and faster process. The paper will serve as a policy bridge that is required to enhance a conscious decision among the powers-that-be in Qatar in order to find a way to harmonize multiple strands of activity and responsibility in the health arena. The end goal will be for Qatar to enhance public awareness and engagement and to integrate effectively the incredible advances in research into healthcare systems, for the benefit of all patients.The PM policy briefing provides concrete recommendations on moving forward with PM initiatives in Qatar and internationally. Equally important, integration of PM within a primary care setting, building a coalition of community champions through awareness and advocacy, finally, communicating PM value, patient engagement/empowerment and education/continued professional development programs of the healthcare workforce.Key recommendations for implementation of precision medicine inside and outside Qatar: 1. Create Community Awareness and PM Education Programs 2. Engage and Empower Patients 3. Communicate PM Value 4. Develop appropriate Infrastructure and Information Management Systems 5. Integrate PM into standard Healthcare System and Ensure Access to Care PM is no longer futuristic. It is here. Implementing PM in routine clinical care does require some investment and infrastructure development. Invariably, cost and lack of expertise are cited as barriers to PM implementation. Equally consequential, are the curriculum and professional development of medical care experts.Policymakers need to lead and coordinate effort among stakeholders and consider cultural and faith perspectives to ensure success. It is essential that policymakers integrate PM approaches into national strategies to improve health and health care for all, and to drive towards the future of medicine precision health.


Subject(s)
Health Policy , Precision Medicine , Humans , Qatar
13.
J Hum Genet ; 65(12): 1067-1073, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32724056

ABSTRACT

Genomics has the potential to revolutionize medical approaches to disease prevention, diagnosis, and treatment, but it does not come without challenges. The success of a national population-based genome program, like the Qatar Genome Program (QGP), depends on the willingness of citizens to donate samples and take up genomic testing services. This study explores public attitudes of the Qatari population toward genetic testing and toward participating in the QGP. A representative sample of 837 adult Qataris was surveyed in May 2016. Approximately 71% of respondents surveyed reported that they were willing to participate in the activities of the QGP. Willingness to participate was significantly associated with basic literacy in genetics, a family history of genetic diseases, and previous experience with genetic testing through premarital screening. Respondents cited the desire to know more about their health status as the principle motivation for participating, while lack of time and information were reported as the most important barriers. With QGP plans to ramp up the scale of its national operation toward more integration into clinical care settings, it is critical to understand public attitudes and their determinants. The results demonstrate public support but also identify the need for more education and individual counseling that not only provide information on the process, challenges, and benefits of genomic testing, but that also address concerns about information security.


Subject(s)
Genetic Diseases, Inborn/diagnosis , Genetic Testing/trends , Public Opinion , Surveys and Questionnaires , Adult , Female , Genetic Diseases, Inborn/genetics , Genetic Diseases, Inborn/psychology , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Qatar/epidemiology , Young Adult
14.
Biochimie ; 175: 93-98, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32479856

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new viral disease that has gained global attention owing to its ability to provoke community and health-care-associated outbreaks of severe infections in human populations. The virus poses serious challenges to clinical management because there are still no approved anti- SARS-CoV-2 drugs available. In this mini-review, we summarize the much updated published reports that demonstrate the mechanism of SARS-CoV-2 entry into host cells, and discuss the availability and development of attractive host-based therapeutic options for SARS-CoV-2 infections.


Subject(s)
Betacoronavirus/metabolism , Betacoronavirus/pathogenicity , Coronavirus Infections/metabolism , Host-Pathogen Interactions/physiology , Pneumonia, Viral/metabolism , Virus Internalization , COVID-19 , Coronavirus Infections/therapy , Humans , Pandemics , Pneumonia, Viral/therapy , SARS-CoV-2
15.
RSC Adv ; 10(59): 36219-36229, 2020 Sep 28.
Article in English | MEDLINE | ID: mdl-35517091

ABSTRACT

A new combination strategy of an active loading and active targeting approach was applied in this work. The liposomes actively loaded with Curcumin (CRM) (LipCRM) were decorated with cholesterol tagged-anti-nucleolin AS1411 aptamer (NCL) via a new post-insertion approach, utilizing the cholesterol as a wedge to incorporate aptamer into the surface of the liposome bilayer. A successful NCL post-insertion was verified by agarose gel electrophoresis and dynamic light scattering (DLS). The cellular uptake of AptNCL-Lip was investigated using flow cytometry and Confocal Laser Scanning Microscopy (CLSM) on two different human breast cancer cell lines (MCF-7 and MDA-MB-231). The uptake and cytotoxicity of loaded CRM were investigated using flow cytometry and MTT assay. Our results showed successful post insertion of NCL aptamer to the surface of Lip. Also, higher cellular uptake was noted for AptNCL-Alexa-LipRhod compared to blank LipRhod in both cell lines. Moreover, CLSM showed prominent endocytosis and uptake of AptNCL-Alexa-LipRhod into the cytoplasm of breast cancer cells. Furthermore, the results showed a significant increase in the uptake and cytotoxicity of AptNCL-LipCRM compared to LipCRM in both cell lines. Overall, our results demonstrate a successful post-insertion of cholesterol-tagged aptamer into liposomes and the possible combination between active loading and active targeting.

16.
medRxiv ; 2020 Dec 21.
Article in English | MEDLINE | ID: mdl-33398295

ABSTRACT

A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,934 COVID-19 cases (713 with severe and 1,221 with mild disease) and 15,251 ancestry-matched population controls across four independent COVID-19 biobanks. We then tested if rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only one rare pLOF mutation across these genes amongst 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We find no evidence of association of rare loss-of-function variants in the proposed 13 candidate genes with severe COVID-19 outcomes.

17.
J Med Chem ; 63(5): 2209-2228, 2020 03 12.
Article in English | MEDLINE | ID: mdl-31369705

ABSTRACT

The c-KIT receptor represents an attractive target for cancer therapy. Aptamers are emerging as a new promising class of nucleic acid therapeutics. In this study, a conventional SELEX approach was applied against the kinase domain of a group of c-KIT proteins (c-KITWT, c-KITD816V, and c-KITD816H) to select aptamers from a random RNA pool that can bind to the kinase domain of each target with high affinity and can selectively interfere with their kinase activities. Interestingly, our data indicated that one candidate aptamer, called V15, can specifically inhibit the in vitro kinase activity of mutant c-KITD816V with an IC50 value that is 9-fold more potent than the sunitinib drug tested under the same conditions. Another aptamer, named as H5/V36, showed the potential to distinguish between the c-KIT kinases by modulating the phosphorylation activity of each in a distinct mechanism of action and in a different potency.


Subject(s)
Aptamers, Nucleotide/pharmacology , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-kit/antagonists & inhibitors , Aptamers, Nucleotide/chemistry , Base Sequence , Cell Line, Tumor , Cell Survival/drug effects , Humans , Phosphorylation/drug effects , Point Mutation , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-kit/genetics , Proto-Oncogene Proteins c-kit/metabolism
18.
Heliyon ; 5(11): e02919, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31844767

ABSTRACT

Combinatorial therapeutic strategies to eradicate tumors can be superior to a single therapeutic modality. Docetaxel (DT) has been approved for the treatment of local or metastasized breast cancer alone or in combination with other chemotherapeutic agents. Thymoquinone (TQ) originated from the seeds of Nigella Sativa plant has been reported to possess in vitro and in vivo antitumor activity against variety of tumors. In the current study, we have investigated the synergistic anticancer efficacy of a novel combination of DT and TQ on MCF7 breast cancer cell line using MTT cell viability assay. Moreover, this study describes for the first time the co-encapsulation of DT and TQ into PEGylated liposomes. The results showed that the combination of DT and TQ resulted in significant synergistic cytotoxicity compared to DT and TQ alone. Moreover, DT and TQ have been successfully co-encapsulated into PEGylated liposomes with higher encapsulation efficiency compared to DT and TQ alone. In conclusion, DT and TQ combination poses a synergistic effect and may aid in decreasing the required doses of DT. Also, the co-encapsulation of DT and TQ into PEGylated liposomes can provide a promising DT and TQ delivery system into cancer cells.

19.
Molecules ; 25(1)2019 Dec 18.
Article in English | MEDLINE | ID: mdl-31861277

ABSTRACT

Soon after they were first described in 1990, aptamers were largely recognized as a new class of biological ligands that can rival antibodies in various analytical, diagnostic, and therapeutic applications. Aptamers are short single-stranded RNA or DNA oligonucleotides capable of folding into complex 3D structures, enabling them to bind to a large variety of targets ranging from small ions to an entire organism. Their high binding specificity and affinity make them comparable to antibodies, but they are superior regarding a longer shelf life, simple production and chemical modification, in addition to low toxicity and immunogenicity. In the past three decades, aptamers have been used in a plethora of therapeutics and drug delivery systems that involve innovative delivery mechanisms and carrying various types of drug cargos. However, the successful translation of aptamer research from bench to bedside has been challenged by several limitations that slow down the realization of promising aptamer applications as therapeutics at the clinical level. The main limitations include the susceptibility to degradation by nucleases, fast renal clearance, low thermal stability, and the limited functional group diversity. The solution to overcome such limitations lies in the chemistry of aptamers. The current review will focus on the recent arts of aptamer chemistry that have been evolved to refine the pharmacological properties of aptamers. Moreover, this review will analyze the advantages and disadvantages of such chemical modifications and how they impact the pharmacological properties of aptamers. Finally, this review will summarize the conjugation strategies of aptamers to nanocarriers for developing targeted drug delivery systems.


Subject(s)
Aptamers, Nucleotide/chemistry , Chemical Phenomena , Drug Carriers/chemistry , Drug Delivery Systems , Humans , Immunoconjugates/chemistry , Ligands , Lipids/chemistry , Molecular Structure , Nanoparticles/chemistry , SELEX Aptamer Technique
20.
RSC Adv ; 9(64): 37148-37161, 2019 Nov 13.
Article in English | MEDLINE | ID: mdl-35542296

ABSTRACT

Curcumin (CRM) is a natural polyphenol with antioxidative, anti-inflammatory, and anticancer therapeutic properties. However, CRM therapeutic potential is limited by low water solubility and bioavailability. Intraliposomal remote loading describes the retention of drugs in liposome cores in response to transmembrane pH gradient. The current study describes for the first time the remote loading of CRM into liposomes using secondary (E-ßCD) and tertiary (D-ßCD) amino-modified ß-cyclodextrins (ßCDs) as carriers and solubilizers. ßCDs were chemically modified to prepare the ionizable weak base functional group followed by forming a guest-host complex of CRM in the modified ßCDs hydrophobic cavities via a solvent evaporation encapsulation technique. These complexes were then actively loaded into preformed liposomes, composed of DPPC/cholesterol (65/35 molar ratio) via pH gradient. The formation of CRM-ßCDs inclusion complexes was characterized using UV-Vis spectroscopy, thermal analysis, and NMR spectroscopy. The complex stoichiometric ratio was determined to be 1 : 1 of CRM-ßCDs based on Job's plot which was also confirmed by the modified Benesi-Hildebrand equation with increasing probability of forming the 1 : 2 ratio of CRM-ßCDs. The apparent formation constants (K f) of 51.6, 100.9 and 55.4 mM-2 were determined for CRM-ßCD, CRM-E-ßCD, and CRM-D-ßCD complexes, respectively. Liposome size, charge and polydispersity index indicate the presence of a homogeneous population before and after active loading. The encapsulation efficiencies of CRM-ßCD complexes into pH gradient preformed liposomes were 16.5, 51.1, and 41.7 for CRM-ßCD, CRM-E-ßCD, and CRM-D-ßCD, respectively, showing more than 5 fold increase compared to normal liposomes. The current study provides a novel remote loading approach utilizing chemically modified cyclodextrins to incorporate hydrophobic drugs into liposomes.

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