Cancer cell-specific oligopeptides selected by an integrated microfluidic system from a phage display library for ovarian cancer diagnosis

Advancements in ovarian cancer immunodiagnostics and therapeutics via phage display technology

Ovarian cancer, ranking as the seventh most prevalent malignancy among women globally, faces significant challenges in diagnosis and therapeutic intervention. The difficulties in early detection are amplified by the limitations and inefficacies inherent in current screening methodologies, highlighting a pressing need for more efficacious diagnostic and treatment strategies. Phage display technology emerges as a pivotal innovation in this context, utilizing extensive phage-peptide libraries to identify ligands with specificity for cancer cell markers, thus enabling precision-targeted therapeutic strategies. This technology promises a paradigm shift in ovarian cancer management, concentrating on targeted drug delivery systems to improve treatment accuracy and efficacy while minimizing adverse effects. Through a meticulous review, this paper evaluates the revolutionary potential of phage display in enhancing ovarian cancer therapy, representing a significant advancement in combating this challenging disease. Phage display technology is heralded as an essential instrument for developing effective immunodiagnostic and therapeutic approaches in ovarian cancer, facilitating early detection, precision-targeted medication, and the implementation of customized treatment plans.

Current Analytical Methods for the Sensitive Assay of New-Generation Ovarian Cancer Drugs in Pharmaceutical and Biological Samples

Ovarian cancer, which affects the female reproductive organs, is one of the most common types of cancer. Since this type of cancer has a high mortality rate from gynaecological cancers, the scientific community shows great interest in studies on its treatment. Chemotherapy, radiotherapy, and surgical treatment methods are used in its treatment. In the absence of targeted treatments in these treatment methods, side effects occur in patients, and patients show resistance to the drug. In addition, the underlying causes of ovarian cancer are still not fully known. The scientific world thinks that genetic factors, environmental conditions, and consumed foods may cause this cancer. The most important factor in the treatment of ovarian cancer is early diagnosis. Therefore, the drugs used in the treatment of ovarian cancer are platinum-based anticancer drugs. In addition to these drugs, the most preferred treatment method recently is targeted treatment approaches using poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors. In this review, studies on the sensitive analysis of the treatment methods of these new-generation drugs used in the treatment of ovarian cancer have been comprehensively examined. In addition, the basic features, structural aspects, and biological data of analytical methods used in treatments with new-generation drugs are explained. Analytical studies carried out in the literature in recent years aim to show future developments in how these new-generation drugs are used today and to guide future studies by comprehensively examining and explaining the structure-activity relationship, mechanism of action, toxicity, and pharmacokinetic studies. Finally, in this study, the methods used in the analysis of drugs used in the treatment of ovarian cancer and the studies conducted between 2015 and 2023 were discussed in detail.

Revolutionizing the female reproductive system research using microfluidic chip platform

Comprehensively understanding the female reproductive system is crucial for safeguarding fertility and preventing diseases concerning women's health. With the capacity to simulate the intricate physio- and patho-conditions, and provide diagnostic platforms, microfluidic chips have fundamentally transformed the knowledge and management of female reproductive health, which will ultimately promote the development of more effective assisted reproductive technologies, treatments, and drug screening approaches. This review elucidates diverse microfluidic systems in mimicking the ovary, fallopian tube, uterus, placenta and cervix, and we delve into the culture of follicles and oocytes, gametes' manipulation, cryopreservation, and permeability especially. We investigate the role of microfluidics in endometriosis and hysteromyoma, and explore their applications in ovarian cancer, endometrial cancer and cervical cancer. At last, the current status of assisted reproductive technology and integrated microfluidic devices are introduced briefly. Through delineating the multifarious advantages and challenges of the microfluidic technology, we chart a definitive course for future research in the woman health field. As the microfluidic technology continues to evolve and advance, it holds great promise for revolutionizing the diagnosis and treatment of female reproductive health issues, thus propelling us into a future where we can ultimately optimize the overall wellbeing and health of women everywhere.

Microfluidic platforms in diagnostic of ovarian cancer

The most important reason for death from ovarian cancer is the late diagnosis of this disease. The standard treatment of ovarian cancer includes surgery and chemotherapy based on platinum, which is associated with side effects for the body. Due to the nonspecific nature of clinical symptoms, developing a platform for early detection of this disease is needed. In recent decades, the advancements of microfluidic devices and systems have provided several advantages for diagnosing ovarian cancer. Designing and manufacturing new platforms using specialized technologies can be a big step toward improving the prevention, diagnosis, and treatment of this group of diseases. Organ-on-a-chip microfluidic devices are increasingly used as a promising platform in cancer research, with a focus on specific biological aspects of the disease. This review focusing on ovarian cancer and microfluidic application technologies in its diagnosis. Additionally, it discusses microfluidic platforms and their potential future perspectives in advancing ovarian cancer diagnosis.

Droplet-based valveless microfluidic system for phage-display screening against spheroids

In this study, we proposed a droplet-based valveless microfluidic system that has the necessary functions to perform the binding, washing, eluting, and collecting processes of phage-display screening against spheroids, which can be expected to present a similar repertoire and number of membrane proteins as in vivo. Although spheroids have much larger sizes than single cells, spheroids are difficult to manipulate through manual operation. The proposed microfluidic system actively controls the position and velocity of droplets using a camera, three air pumps, and three liquid pumps to perform the processes for phage-display screening. The cross section of the microchannel is large in width and height for the passage of spheroids. Valves that can close such a large cross-sectional microchannel are not readily available. Thus, we proposed valveless flow control using liquid pumps. In addition, the proposed microfluidic system involves complex flow channels with airflow subchannels to perform phage-display screening. For washing, nonspecific-binding phages remaining in the flow channels must be minimized. The proposed microfluidic system can perform selective blocking and flush washing. Selective blocking can prevent the airflow channels from becoming hydrophilic with blocking liquid, and flush washing can flush phages remaining in the flow channel. We experimentally verified the functions of the developed microfluidic device based on the proposed system.

Rapid On-Cell Selection of High-Performance Human Antibodies

Phage display is a critical tool for developing antibodies. However, existing approaches require many time-consuming rounds of biopanning and screening of potential candidates due to a high rate of failure during validation. Herein, we present a rapid on-cell phage display platform which recapitulates the complex in vivo binding environment to produce high-performance human antibodies in a short amount of time. Selection is performed in a highly stringent heterogeneous mixture of cells to quickly remove nonspecific binders. A microfluidic platform then separates antigen-presenting cells with high throughput and specificity. An unsupervised machine learning algorithm analyzes sequences of phage from all pools to identify the structural trends that contribute to affinity and proposes ideal candidates for validation. In a proof-of-concept screen against human Frizzled-7, a key ligand in the Wnt signaling pathway, antibodies with picomolar affinity were discovered in two rounds of selection that outperformed current gold-standard reagents. This approach, termed μCellect, is low cost, high throughput, and compatible with a wide variety of cell types, enabling widespread adoption for antibody development.

OUP accepted manuscript

BACKGROUND

To provide the optimal milieu for implantation and fetal development, the female reproductive system must orchestrate uterine dynamics with the appropriate hormones produced by the ovaries. Mature oocytes may be fertilized in the fallopian tubes, and the resulting zygote is transported toward the uterus, where it can implant and continue developing. The cervix acts as a physical barrier to protect the fetus throughout pregnancy, and the vagina acts as a birth canal (involving uterine and cervix mechanisms) and facilitates copulation. Fertility can be compromised by pathologies that affect any of these organs or processes, and therefore, being able to accurately model them or restore their function is of paramount importance in applied and translational research. However, innate differences in human and animal model reproductive tracts, and the static nature of 2D cell/tissue culture techniques, necessitate continued research and development of dynamic and more complex in vitro platforms, ex vivo approaches and in vivo therapies to study and support reproductive biology. To meet this need, bioengineering is propelling the research on female reproduction into a new dimension through a wide range of potential applications and preclinical models, and the burgeoning number and variety of studies makes for a rapidly changing state of the field.

OBJECTIVE AND RATIONALE

This review aims to summarize the mounting evidence on bioengineering strategies, platforms and therapies currently available and under development in the context of female reproductive medicine, in order to further understand female reproductive biology and provide new options for fertility restoration. Specifically, techniques used in, or for, the uterus (endometrium and myometrium), ovary, fallopian tubes, cervix and vagina will be discussed.

SEARCH METHODS

A systematic search of full-text articles available in PubMed and Embase databases was conducted to identify relevant studies published between January 2000 and September 2021. The search terms included: bioengineering, reproduction, artificial, biomaterial, microfluidic, bioprinting, organoid, hydrogel, scaffold, uterus, endometrium, ovary, fallopian tubes, oviduct, cervix, vagina, endometriosis, adenomyosis, uterine fibroids, chlamydia, Asherman’s syndrome, intrauterine adhesions, uterine polyps, polycystic ovary syndrome and primary ovarian insufficiency. Additional studies were identified by manually searching the references of the selected articles and of complementary reviews. Eligibility criteria included original, rigorous and accessible peer-reviewed work, published in English, on female reproductive bioengineering techniques in preclinical (in vitro/in vivo/ex vivo) and/or clinical testing phases.

OUTCOMES

Out of the 10 390 records identified, 312 studies were included for systematic review. Owing to inconsistencies in the study measurements and designs, the findings were assessed qualitatively rather than by meta-analysis. Hydrogels and scaffolds were commonly applied in various bioengineering-related studies of the female reproductive tract. Emerging technologies, such as organoids and bioprinting, offered personalized diagnoses and alternative treatment options, respectively. Promising microfluidic systems combining various bioengineering approaches have also shown translational value.

WIDER IMPLICATIONS

The complexity of the molecular, endocrine and tissue-level interactions regulating female reproduction present challenges for bioengineering approaches to replace female reproductive organs. However, interdisciplinary work is providing valuable insight into the physicochemical properties necessary for reproductive biological processes to occur. Defining the landscape of reproductive bioengineering technologies currently available and under development for women can provide alternative models for toxicology/drug testing, ex vivo fertility options, clinical therapies and a basis for future organ regeneration studies.

Phage nanofibers in nanomedicine: Biopanning for early diagnosis, targeted therapy, and proteomics analysis

Display of a peptide or protein of interest on the filamentous phage (also known as bacteriophage), a biological nanofiber, has opened a new route for disease diagnosis and therapy as well as proteomics. Earlier phage display was widely used in protein-protein or antigen-antibody studies. In recent years, its application in nanomedicine is becoming increasingly popular and encouraging. We aim to review the current status in this research direction. For better understanding, we start with a brief introduction of basic biology and structure of the filamentous phage. We present the principle of phage display and library construction method on the basis of the filamentous phage. We summarize the use of the phage displayed peptide library for selecting peptides with high affinity against cells or tissues. We then review the recent applications of the selected cell or tissue targeting peptides in developing new targeting probes and therapeutics to advance the early diagnosis and targeted therapy of different diseases in nanomedicine. We also discuss the integration of antibody phage display and modern proteomics in discovering new biomarkers or target proteins for disease diagnosis and therapy. Finally, we propose an outlook for further advancing the potential impact of phage display on future nanomedicine. This article is categorized under: Biology-Inspired Nanomaterials > Protein and Virus-Based Structures.

Microfluidic Device for Screening for Target Cell-Specific Binding Molecules by Using Adherent Cells

This paper proposes a microfluidic device for screening molecules such as aptamers, antibodies, proteins, etc. for target cell-specific binding molecules. The discovery of cancer cell-specific binding molecules was the goal of this study. Its functions include filtering non-target cell-binding molecules, trapping molecules on the surface of target cells, washing away unbound molecules, and collecting target cell-specific binding molecules from target cells. These functions were effectively implemented by using our previously developed micro pillar arrays for cell homogeneous dispersion and pneumatic microvalves for tall microchannels. The device was also equipped with serially connected filter chambers in which non-target cells were cultured to reduce the molecules binding to non-target cells as much as possible. We evaluated the performance of the device using cancer cell lines (N87 cells as target cells and HeLa cells as non-target cells) and two fluorescent dye-labeled antibodies: Anti-human epidermal growth factor receptor 2 (anti-HER2) antibody that binds to target cells and anti-integrin antibody that binds to non-target cells. The results showed that the device could reduce anti-integrin antibodies to the detection limit of fluorescent measurement and collect anti-HER2 antibodies from the target cells.

Microfluidic platforms for rapid screening of cancer affinity reagents by using tissue samples

Cancer is the most serious disease worldwide, and ovarian cancer (OvCa) is the second most common type of gynecological cancer. There is consequently an urgent need for early-stage detection of OvCa, which requires affinity reagent biomarkers for OvCa. Systematic evolution of ligands by exponential enrichment (SELEX) and phage display technology are two powerful technologies for identifying affinity reagent biomarkers. However, the benchtop protocols for both screening technologies are relatively lengthy and require well-trained personnel. We therefore developed a novel, integrated microfluidic system capable of automating SELEX and phage display technology. Instead of using cancer cell lines, it is the first work which used tissue slides as screening targets, which possess more complicated and uncovered information for affinity reagents to recognize. This allowed for the identification of aptamer (nucleic acid) and peptide probes specific to OvCa cells and tissues. Furthermore, this developed system could be readily modified to uncover affinity reagents for diagnostics or even target therapy of other cancer cell types in the future.

Structure-based design for binding peptides in anti-cancer therapy

The conventional anticancer therapeutics usually lack cancer specificity, leading to damage of normal tissues that patients find hard to tolerate. Ideally, anticancer therapeutics carrying payloads of drugs equipped with cancer targeting peptides can act like "guided missiles" with the capacity of targeted delivery toward many types of cancers. Peptides are amenable for conjugation to nano drugs for functionalization, thereby improving drug delivery and cellular uptake in cancer-targeting therapies. Peptide drugs are often more difficult to design through molecular docking and in silico analysis than small molecules, because peptide structures are more flexible, possess intricate molecular conformations, and undergo complex interactions. In this review, the development and application of strategies for structure-based design of cancer-targeting peptides against GRP78 are discussed. This Review also covers topics related to peptide pharmacokinetics and targeting delivery, including molecular docking studies, features that provide advantages for in vivo use, and properties that influence the cancer-targeting ability. Some advanced technologies and special peptides that can overcome the pharmacokinetic challenges have also been included.

Microphysiologic systems in female reproductive biology

Microphysiologic systems (MPS), including new organ-on-a-chip technologies, recapitulate tissue microenvironments by employing specially designed tissue or cell culturing techniques and microfluidic flow. Such systems are designed to incorporate physiologic factors that conventional 2D or even 3D systems cannot, such as the multicellular dynamics of a tissue-tissue interface or physical forces like fluid sheer stress. The female reproductive system is a series of interconnected organs that are necessary to produce eggs, support embryo development and female health, and impact the functioning of non-reproductive tissues throughout the body. Despite its importance, the human reproductive tract has received less attention than other organ systems, such as the liver and kidney, in terms of modeling with MPS. In this review, we discuss current gaps in the field and areas for technological advancement through the application of MPS. We explore current MPS research in female reproductive biology, including fertilization, pregnancy, and female reproductive tract diseases, with a focus on their clinical applications. Impact statement This review discusses existing microphysiologic systems technology that may be applied to study of the female reproductive tract, and those currently in development to specifically investigate gametes, fertilization, embryo development, pregnancy, and diseases of the female reproductive tract. We focus on the clinical applicability of these new technologies in fields such as assisted reproductive technologies, drug testing, disease diagnostics, and personalized medicine.

Phage display-derived oligopeptide-functionalized probes for in vivo specific photoacoustic imaging of osteosarcoma

Specific detection of various tumor types remains crucial for designing effective treatment strategies. We demonstrate photoacoustic imaging (PAI) using high-affinity and high-specificity peptide-based probes for accurate and specific diagnosis of osteosarcoma. Herein, two new tumor-specific oligopeptides, termed PT6 and PT7, were identified using phage display-based screening on an osteosarcoma cell line (UMR-106). The identified oligopeptides were able to detect clinical osteosarcoma samples on tissue microarrays. Oligopeptide-conjugated PEGylated gold nanorods (PGNR) were designed to specifically target UMR-106 cells. More importantly, PAI revealed that both PGNR-PT6 and PGNR-PT7 could bind selectively to subcutaneous UMR-106 xenografts after systemic administration and enhance the contrast of osteosarcoma images by 170% and 230%, respectively, compared to tumor-bearing mice injected with PGNRs conjugated to scrambled oligopeptides. PAI employing PGNRs conjugated to specifically designed nanoprobes may provide a new method for tumor type-specific diagnosis of osteosarcoma.

Continuous microfluidic assortment of interactive ligands (CMAIL)

Finding an interactive ligand-receptor pair is crucial to many applications, including the development of monoclonal antibodies. Biopanning, a commonly used technique for affinity screening, involves a series of washing steps and is lengthy and tedious. Here we present an approach termed continuous microfluidic assortment of interactive ligands, or CMAIL, for the screening and sorting of antigen-binding single-chain variable antibody fragments (scFv) displayed on bacteriophages (phages). Phages carrying native negative charges on their coat proteins were electrophoresed through a hydrogel matrix functionalized with target antigens under two alternating orthogonal electric fields. During the weak horizontal electric field phase, phages were differentially swept laterally depending on their affinity for the antigen, and all phages were electrophoresed down to be collected during the strong vertical electric field phase. Phages of different affinity were spatially separated, allowing the continuous operation. More than 10⁵ CFU (colony forming unit) antigen-interacting phages were isolated with ~100% specificity from a phage library containing 3 × 10⁹ individual members within 40 minutes of sorting using CMAIL. CMAIL is rapid, sensitive, specific, and does not employ washing, elution or magnetic beads. In conclusion, we have developed an efficient and cost-effective method for isolating and sorting affinity reagents involving phage display.

Microfluidics in the selection of affinity reagents for the detection of cancer: paving a way towards future diagnostics

Microfluidic technologies have miniaturized a variety of biomedical applications, and these chip-based systems have several significant advantages over their large-scale counterparts. Recently, this technology has been used for automating labor-intensive and time-consuming screening processes, whereby affinity reagents, including aptamers, peptides, antibodies, polysaccharides, glycoproteins, and a variety of small molecules, are used to probe for molecular biomarkers. When compared to conventional methods, the microfluidic approaches are faster, more compact, require considerably smaller quantities of samples and reagents, and can be automated. Furthermore, they allow for more precise control of reaction conditions (e.g., pH, temperature, and shearing forces) such that more efficient screening can be performed. A variety of affinity reagents for targeting cancer cells or cancer biomarkers are now available and will likely replace conventional antibodies. In this review article, the selection of affinity reagents for cancer cells or cancer biomarkers on microfluidic platforms is reviewed with the aim of highlighting the utility of such approaches in cancer diagnostics.

Advance in phage display technology for bioanalysis

Phage display technology has emerged as a powerful tool for target gene expression and target-specific ligand selection. It is widely used to screen peptides, proteins and antibodies with the advantages of simplicity, high efficiency and low cost. A variety of targets, including ions, small molecules, inorganic materials, natural and biological polymers, nanostructures, cells, bacteria, and even tissues, have been demonstrated to generate specific binding ligands by phage display. Phages and target-specific ligands screened by phage display have been widely used as affinity reagents in therapeutics, diagnostics and biosensors. In this review, comparisons of different types of phage display systems are first presented. Particularly, microfluidic-based phage display, which enables screening with high throughput, high efficiency and integration, is highlighted. More importantly, we emphasize the advances in biosensors based on phages or phage-derived probes, including nonlytic phages, lytic phages, peptides or proteins screened by phage display, phage assemblies and phage-nanomaterial complexes. However, more efficient and higher throughput phage display methods are still needed to meet an explosion in demand for bioanalysis. Furthermore, screening of cyclic peptides and functional peptides will be the hotspot in bioanalysis.

An integrated microfluidic system for screening of phage-displayed peptides specific to colon cancer cells and colon cancer stem cells

Affinity reagents recognizing biomarkers specifically are essential components of clinical diagnostics and target therapeutics. However, conventional methods for screening of these reagents often have drawbacks such as large reagent consumption, the labor-intensive or time-consuming procedures, and the involvement of bulky or expensive equipment. Alternatively, microfluidic platforms could potentially automate the screening process within a shorter period of time and reduce reagent and sample consumption dramatically. It has been demonstrated recently that a subpopulation of tumor cells known as cancer stem cells possess high drug resistance and proliferation potential and are regarded as the main cause of metastasis. Therefore, a peptide that recognizes cancer stem cells and differentiates them from other cancer cells will be extremely useful in early diagnosis and target therapy. This study utilized M13 phage display technology to identify peptides that bind, respectively, to colon cancer cells and colon cancer stem cells using an integrated microfluidic system. In addition to positive selection, a negative selection process was integrated on the chip to achieve the selection of peptides of high affinity and specificity. We successfully screened three peptides specific to colon cancer cells and colon cancer stem cells, namely, HOLC-1, HOLC-2, and COLC-1, respectively, and their specificity was measured by the capture rate between target, control, and other cell lines. The capture rates are 43.40 ± 7.23%, 45.16 ± 7.12%, and 49.79 ± 5.34% for colon cancer cells and colon cancer stem cells, respectively, showing a higher specificity on target cells than on control and other cell lines. The developed technique may be promising for early diagnosis of cancer cells and target therapeutics.