1
|
Valentini L, Pacini L, Errante F, Morchio C, Sanna B, Rovero P, Morabito A. Peptide-Functionalized Silk Fibers as a Platform to Stabilize Gelatin for Use in Ingestible Devices. Molecules 2022; 27:molecules27144605. [PMID: 35889483 PMCID: PMC9318617 DOI: 10.3390/molecules27144605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/15/2022] [Accepted: 07/17/2022] [Indexed: 11/17/2022] Open
Abstract
The combination of pharmacologic and endoscopic therapies is the gold standard for treating intestinal failures. The possibility of chemical solubility in water is mandatory for intelligent capsules. Functionalised silk fibroin with peptides and covalently linking different molecular entities to its structure make this protein a platform for preparing gels dissolving in the small and large intestine for drug delivery. In the present study, we linked a peptide containing the cell-adhesive motif Arginine–Glycine–Aspartic acid (RGD) to degummed silk fibres (DSF). Regenerated silk fibroin (RS) films obtained by dissolving functionalised DSF in formic acid were used to prepare composite gelatin. We show that such composite gelatin remains stable and elastic in the simulated gastric fluid (SGF) but can dissolve in the small and large intestines’ neutral-pH simulated intestine fluid (SIF). These findings open up the possibility of designing microfabricated and physically programmable scaffolds that locally promote tissue regeneration, thanks to bio-enabled materials based on functionalised regenerated silk.
Collapse
Affiliation(s)
- Luca Valentini
- Civil and Environmental Engineering Department, University of Perugia, Strada di Pentima 4, 05100 Terni, Italy
- Correspondence:
| | - Lorenzo Pacini
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry “Ugo Schiff”, University of Florence, 59100 Sesto Fiorentino, Italy;
| | - Fosca Errante
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of NeuroFarBa, University of Florence, 50019 Sesto Fiorentino, Italy; (F.E.); (P.R.)
| | - Cecilia Morchio
- Dipartimento Neuroscienze, Psicologia, Area del Farmaco e della Salute del Bambino NEUROFARBA, Università degli Studi di Firenze, Viale Pieraccini 6, 50121 Firenze, Italy; (C.M.); (B.S.); (A.M.)
| | - Beatrice Sanna
- Dipartimento Neuroscienze, Psicologia, Area del Farmaco e della Salute del Bambino NEUROFARBA, Università degli Studi di Firenze, Viale Pieraccini 6, 50121 Firenze, Italy; (C.M.); (B.S.); (A.M.)
| | - Paolo Rovero
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of NeuroFarBa, University of Florence, 50019 Sesto Fiorentino, Italy; (F.E.); (P.R.)
| | - Antonino Morabito
- Dipartimento Neuroscienze, Psicologia, Area del Farmaco e della Salute del Bambino NEUROFARBA, Università degli Studi di Firenze, Viale Pieraccini 6, 50121 Firenze, Italy; (C.M.); (B.S.); (A.M.)
| |
Collapse
|
2
|
Kaffash E, Ali Shahbazi M, Hatami H, Nokhodchi A. An insight into gastrointestinal macromolecule delivery using physical oral devices. Drug Discov Today 2022; 27:2309-2321. [PMID: 35460891 DOI: 10.1016/j.drudis.2022.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/25/2022] [Accepted: 04/13/2022] [Indexed: 11/03/2022]
Abstract
Oral delivery is preferred over other routes of drug administration by both patients and physicians. The bioavailability of some therapeutics that are delivered via the oral route is restricted due to the protease- and bacteria-rich environment in the gastrointestinal tract, and by the pH variability along the delivery route. Given these harsh environments, the oral delivery of therapeutic macromolecules is complicated and remains challenging. Various formulation approaches, including the use of permeation enhancers and nanosized carriers, as well as chemical alteration of the drug structure, have been studied as ways to improve the oral absorption of macromolecular drugs. Nevertheless, the bioavailability of marketed oral peptide medicines is often relatively poor. This review highlights the most recent and promising physical methods for improving the oral bioavailability of macromolecules such as peptides. These methods include microneedle injections, high-speed stream injectors, magnetic drug targeting, expandable hydrogels, and iontophoresis. We highlight the potential and challenges of these new technologies, which may impact the future approaches used by pharmaceutical companies to create more efficient and safer orally administered macromolecules. Teaser: Despite substantial effort, the oral delivery of macromolecules remains challenging due to their low bioavailability. This review discusses the potential, challenges, and safety concerns associated with new technologies and devices for oral macromolecule delivery.
Collapse
Affiliation(s)
- Ehsan Kaffash
- Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Ali Shahbazi
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands; Zanjan Pharmaceutical Nanotechnology Research Center (ZPNRC), Zanjan University of Medical Sciences, 45139-56184 Zanjan, Iran.
| | - Hooman Hatami
- Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Nokhodchi
- Pharmaceutics Research Laboratory, School of Life Sciences, University of Sussex, Brighton, UK.
| |
Collapse
|
3
|
Abstract
In conventional classification, soft robots feature mechanical compliance as the main distinguishing factor from traditional robots made of rigid materials. Recent advances in functional soft materials have facilitated the emergence of a new class of soft robots capable of tether-free actuation in response to external stimuli such as heat, light, solvent, or electric or magnetic field. Among the various types of stimuli-responsive materials, magnetic soft materials have shown remarkable progress in their design and fabrication, leading to the development of magnetic soft robots with unique advantages and potential for many important applications. However, the field of magnetic soft robots is still in its infancy and requires further advancements in terms of design principles, fabrication methods, control mechanisms, and sensing modalities. Successful future development of magnetic soft robots would require a comprehensive understanding of the fundamental principle of magnetic actuation, as well as the physical properties and behavior of magnetic soft materials. In this review, we discuss recent progress in the design and fabrication, modeling and simulation, and actuation and control of magnetic soft materials and robots. We then give a set of design guidelines for optimal actuation performance of magnetic soft materials. Lastly, we summarize potential biomedical applications of magnetic soft robots and provide our perspectives on next-generation magnetic soft robots.
Collapse
Affiliation(s)
- Yoonho Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xuanhe Zhao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
4
|
Luo Z, Paunović N, Leroux JC. Physical methods for enhancing drug absorption from the gastrointestinal tract. Adv Drug Deliv Rev 2021; 175:113814. [PMID: 34052229 DOI: 10.1016/j.addr.2021.05.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/17/2021] [Accepted: 05/20/2021] [Indexed: 01/01/2023]
Abstract
Overcoming the gastrointestinal (GI) barriers is a formidable challenge in the oral delivery of active macromolecules such as peptide- and protein- based drugs. In the past four decades, a plethora of formulation strategies ranging from permeation enhancers, nanosized carriers, and chemical modifications of the drug's structure has been investigated to increase the oral absorption of these macromolecular compounds. However, only limited successes have been achieved so far, with the bioavailability of marketed oral peptide drugs remaining generally very low. Recently, a few approaches that are based on physical interactions, such as magnetic, acoustic, and mechanical forces, have been explored in order to control and improve the drug permeability across the GI mucosa. Although in the early stages, some of these methods have shown great potential both in terms of improved bioavailability and spatiotemporal delivery of drugs. Here, we offer a concise, yet critical overview of these rather unconventional technologies with a particular focus on their potential and possible challenges for further clinical translation.
Collapse
|
5
|
Liu X, Yang Y, Inda ME, Lin S, Wu J, Kim Y, Chen X, Ma D, Lu TK, Zhao X. Magnetic Living Hydrogels for Intestinal Localization, Retention, and Diagnosis. ADVANCED FUNCTIONAL MATERIALS 2021; 31:2010918. [PMID: 35903441 PMCID: PMC9328153 DOI: 10.1002/adfm.202010918] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Natural microbial sensing circuits can be rewired into new gene networks to build living sensors that detect and respond to disease-associated biomolecules. However, synthetic living sensors, once ingested, are cleared from the gastrointestinal (GI) tract within 48 hours; retaining devices in the intestinal lumen is prone to intestinal blockage or device migration. To localize synthetic microbes and safely extend their residence in the GI tract for health monitoring and sustained drug release, an ingestible magnetic hydrogel carrier is developed to transport diagnostic microbes to specific intestinal sites. The magnetic living hydrogel is localized and retained by attaching a magnet to the abdominal skin, resisting the peristaltic waves in the intestine. The device retention is validated in a human intestinal phantom and an in vivo rodent model, showing that the ingestible hydrogel maintains the integrated living bacteria for up to seven days, which allows the detection of heme for GI bleeding in the harsh environment of the gut. The retention of microelectronics is also demonstrated by incorporating a temperature sensor into the magnetic hydrogel carrier.
Collapse
Affiliation(s)
- Xinyue Liu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yueying Yang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Maria Eugenia Inda
- Synthetic Biology Group, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shaoting Lin
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jingjing Wu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yoonho Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xiaoyu Chen
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dacheng Ma
- Synthetic Biology Group, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Timothy K Lu
- Synthetic Biology Group, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xuanhe Zhao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
6
|
Schneider F, Koziolek M, Weitschies W. In Vitro and In Vivo Test Methods for the Evaluation of Gastroretentive Dosage Forms. Pharmaceutics 2019; 11:E416. [PMID: 31426417 PMCID: PMC6723944 DOI: 10.3390/pharmaceutics11080416] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/07/2019] [Accepted: 08/12/2019] [Indexed: 12/16/2022] Open
Abstract
More than 50 years ago, the first concepts for gastroretentive drug delivery systems were developed. Despite extensive research in this field, there is no single formulation concept for which reliable gastroretention has been demonstrated under different prandial conditions. Thus, gastroretention remains the holy grail of oral drug delivery. One of the major reasons for the various setbacks in this field is the lack of predictive in vitro and in vivo test methods used during preclinical development. In most cases, human gastrointestinal physiology is not properly considered, which leads to the application of inappropriate in vitro and animal models. Moreover, conditions in the stomach are often not fully understood. Important aspects such as the kinetics of fluid volumes, gastric pH or mechanical stresses have to be considered in a realistic manner, otherwise, the gastroretentive potential as well as drug release of novel formulations cannot be assessed correctly in preclinical studies. This review, therefore, highlights the most important aspects of human gastrointestinal physiology and discusses their potential implications for the evaluation of gastroretentive drug delivery systems.
Collapse
Affiliation(s)
- Felix Schneider
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany
| | - Mirko Koziolek
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany
| | - Werner Weitschies
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany.
| |
Collapse
|
7
|
Umay I, Fidan B, Barshan B. Localization and Tracking of Implantable Biomedical Sensors. SENSORS (BASEL, SWITZERLAND) 2017; 17:E583. [PMID: 28335384 PMCID: PMC5375869 DOI: 10.3390/s17030583] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/27/2017] [Accepted: 03/06/2017] [Indexed: 01/20/2023]
Abstract
Implantable sensor systems are effective tools for biomedical diagnosis, visualization and treatment of various health conditions, attracting the interest of researchers, as well as healthcare practitioners. These systems efficiently and conveniently provide essential data of the body part being diagnosed, such as gastrointestinal (temperature, pH, pressure) parameter values, blood glucose and pressure levels and electrocardiogram data. Such data are first transmitted from the implantable sensor units to an external receiver node or network and then to a central monitoring and control (computer) unit for analysis, diagnosis and/or treatment. Implantable sensor units are typically in the form of mobile microrobotic capsules or implanted stationary (body-fixed) units. In particular, capsule-based systems have attracted significant research interest recently, with a variety of applications, including endoscopy, microsurgery, drug delivery and biopsy. In such implantable sensor systems, one of the most challenging problems is the accurate localization and tracking of the microrobotic sensor unit (e.g., robotic capsule) inside the human body. This article presents a literature review of the existing localization and tracking techniques for robotic implantable sensor systems with their merits and limitations and possible solutions of the proposed localization methods. The article also provides a brief discussion on the connection and cooperation of such techniques with wearable biomedical sensor systems.
Collapse
Affiliation(s)
- Ilknur Umay
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
| | - Barış Fidan
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
| | - Billur Barshan
- Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, Ankara TR-06800, Turkey.
| |
Collapse
|
8
|
Seth A, Lafargue D, Poirier C, Badier T, Delory N, Laporte A, Delbos JM, Jeannin V, Péan JM, Ménager C. Optimization of magnetic retention in the gastrointestinal tract: Enhanced bioavailability of poorly permeable drug. Eur J Pharm Sci 2017; 100:25-35. [DOI: 10.1016/j.ejps.2016.12.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/08/2016] [Accepted: 12/20/2016] [Indexed: 11/30/2022]
|
9
|
Huang L, Xu F, Guo B, Ma J, Zhao J. Morphological study of dynamic culture of thermosensitive collagen hydrogel in constructing tissue engineering complex. Bioengineered 2016; 7:266-73. [PMID: 27459597 DOI: 10.1080/21655979.2016.1197741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
ABSTACT The purpose of this study is to research the morphologies and functional characteristics of the cell-scaffold complex in vitro constructed under dynamic culture conditions. BMSCs were isolated from the long bones of Fischer344 rats, and performed in vitro amplification to the third generation as seed cells, together with thermosensitive collagen hydrogel (TCH) as cell adhesion matrix, and poly-L-lactic acid (PLLA) as scaffold, to construct cell-scaffold complex. The cell-scaffold complexes in the experiment group and the control group were then performed dynamic culture and static culture. After 7 d of in vitro culture, the complexes in the 2 groups were performed gross observation and SEM; meanwhile, the total DNA content in the complex was detected on D0,1,3, and 7 of culture. After cultured using these 2 ways, collagen could both wrap the PLLA scaffold, forming dense film-like structures on the PLLA surface. The total DNA contents in the cell-scaffold complex of the experiment group on D1,3, and 7 were significantly higher than the control group (P < 0.05). Compared with D0, the total DNA contents on D1,3, and 7 in both groups were gradually increased, but only the total DNA contents on D7 showed statistically significant difference than D0 (P < 0.05). TCH -PLLA fiber joint-constructed complex extracellular matrix had good biocompatibility, and dynamic culture could promote the distribution of BMSCs on the surface and inside the structure, thus promoting cell proliferation, so it could be used for the in vitro construction of tissue engineering complex.
Collapse
Affiliation(s)
- Lanfeng Huang
- a Department of Orthopedics , The Second Hospital of Jilin University , Changchun , China
| | - Feixiang Xu
- a Department of Orthopedics , The Second Hospital of Jilin University , Changchun , China
| | - Bin Guo
- a Department of Orthopedics , The Second Hospital of Jilin University , Changchun , China
| | - Jianchao Ma
- a Department of Orthopedics , The Second Hospital of Jilin University , Changchun , China
| | - Jinsong Zhao
- b Department of Ophthalmology , The Second Hospital of Jilin University , Changchun , China
| |
Collapse
|
10
|
Zhang S, Bellinger AM, Glettig DL, Barman R, Lee YAL, Zhu J, Cleveland C, Montgomery VA, Gu L, Nash LD, Maitland DJ, Langer R, Traverso G. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices. NATURE MATERIALS 2015; 14:1065-1071. [PMID: 26213897 PMCID: PMC4772966 DOI: 10.1038/nmat4355] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 06/17/2015] [Indexed: 05/19/2023]
Abstract
Devices resident in the stomach-used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery-typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastric-retentive devices.
Collapse
Affiliation(s)
- Shiyi Zhang
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Andrew M. Bellinger
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Dean L. Glettig
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Ross Barman
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Young-Ah Lucy Lee
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Jiahua Zhu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Cody Cleveland
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Veronica A Montgomery
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Li Gu
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Landon D. Nash
- Department of Biomedical Engineering, Biomedical Device Laboratory, Texas A&M University, College Station, TX 77843
| | - Duncan J. Maitland
- Department of Biomedical Engineering, Biomedical Device Laboratory, Texas A&M University, College Station, TX 77843
| | - Robert Langer
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
- Harvard–MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139
- To whom correspondence may be addressed. or
| | - Giovanni Traverso
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
- To whom correspondence may be addressed. or
| |
Collapse
|
11
|
Than TD, Alici G, Harvey S, Zhou H, Li W. Concept and simulation study of a novel localization method for robotic endoscopic capsules using multiple positron emission markers. Med Phys 2015; 41:072501. [PMID: 24989404 DOI: 10.1118/1.4881316] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Over the last decade, wireless capsule endoscope has been the tool of choice for noninvasive inspection of the gastrointestinal tract, especially in the small intestine. However, the latest clinical products have not been equipped with a sufficiently accurate localization system which makes it difficult to determine the location of intestinal abnormalities, and to apply follow-up interventions such as biopsy or drug delivery. In this paper, the authors present a novel localization method based on tracking three positron emission markers embedded inside an endoscopic capsule. METHODS Three spherical(22)Na markers with diameters of less than 1 mm are embedded in the cover of the capsule. Gamma ray detectors are arranged around a patient body to detect coincidence gamma rays emitted from the three markers. The position of each marker can then be estimated using the collected data by the authors' tracking algorithm which consists of four consecutive steps: a method to remove corrupted data, an initialization method, a clustering method based on the Fuzzy C-means clustering algorithm, and a failure prediction method. RESULTS The tracking algorithm has been implemented inMATLAB utilizing simulation data generated from the Geant4 Application for Emission Tomography toolkit. The results show that this localization method can achieve real-time tracking with an average position error of less than 0.4 mm and an average orientation error of less than 2°. CONCLUSIONS The authors conclude that this study has proven the feasibility and potential of the proposed technique in effectively determining the position and orientation of a robotic endoscopic capsule.
Collapse
Affiliation(s)
- Trung Duc Than
- School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522, Australia
| | - Gursel Alici
- School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522, Australia
| | - Steven Harvey
- Department of Nuclear Medicine, Wollongong Hospital, New South Wales 2500, Australia
| | - Hao Zhou
- School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522, Australia
| | - Weihua Li
- School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522, Australia
| |
Collapse
|
12
|
Seth A, Lafargue D, Poirier C, Péan JM, Ménager C. Performance of magnetic chitosan–alginate core–shell beads for increasing the bioavailability of a low permeable drug. Eur J Pharm Biopharm 2014; 88:374-81. [DOI: 10.1016/j.ejpb.2014.05.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 04/22/2014] [Accepted: 05/16/2014] [Indexed: 10/25/2022]
|
13
|
Huang L, Li R, Liu W, Dai J, Du Z, Wang X, Ma J, Zhao J. Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve. Neural Regen Res 2014; 9:1371-8. [PMID: 25221594 PMCID: PMC4160868 DOI: 10.4103/1673-5374.137590] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2014] [Indexed: 12/15/2022] Open
Abstract
Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, but cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhesion stage. Moreover, seeded cells were distributed throughout the material.
Collapse
Affiliation(s)
- Lanfeng Huang
- Department of Joint Surgery, Orthopedics Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Rui Li
- Centre of Hand & Foot Surgery and Reparative & Reconstructive Surgery, Orthopedics Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Wanguo Liu
- Department of Orthopedics Surgery, the Third Hospital of Jilin University, Changchun, Jilin Province, China
| | - Jin Dai
- Department of Joint Surgery, Orthopedics Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Zhenwu Du
- Institute of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Xiaonan Wang
- Department of Joint Surgery, Orthopedics Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Jianchao Ma
- Department of Joint Surgery, Orthopedics Hospital of the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Jinsong Zhao
- Department of Ophthalmology, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| |
Collapse
|
14
|
Li Y, Huang G, Zhang X, Wang L, Du Y, Lu TJ, Xu F. Engineering cell alignment in vitro. Biotechnol Adv 2014; 32:347-65. [DOI: 10.1016/j.biotechadv.2013.11.007] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Revised: 11/16/2013] [Accepted: 11/17/2013] [Indexed: 01/03/2023]
|
15
|
Drug carriers for oral delivery of peptides and proteins: accomplishments and future perspectives. Ther Deliv 2013; 4:251-65. [PMID: 23343163 DOI: 10.4155/tde.12.143] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Effective formulation for peptide and protein delivery through the oral route has always been the critical effort with the advent of biotechnology. Stability, enzymatic degradation and ineffective absorption are common difficulties found for conventional dosage forms. As a result, new drug-delivery approaches are used to circumvent these limitations and enhance effective oral drug delivery. Some of these technologies have reached late stages of clinical trials and promising results will be available in the near future. This review covers, in general, the recent carriers reported in literature.
Collapse
|
16
|
Xu F, Inci F, Mullick O, Gurkan UA, Sung Y, Kavaz D, Li B, Denkbas EB, Demirci U. Release of magnetic nanoparticles from cell-encapsulating biodegradable nanobiomaterials. ACS NANO 2012; 6:6640-9. [PMID: 22680777 PMCID: PMC3813440 DOI: 10.1021/nn300902w] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The future of tissue engineering requires development of intelligent biomaterials using nanoparticles. Magnetic nanoparticles (MNPs) have several applications in biology and medicine; one example is Food and Drug Administration (FDA)-approved contrast agents in magnetic resonance imaging. Recently, MNPs have been encapsulated within cell-encapsulating hydrogels to create novel nanobiomaterials (i.e., M-gels), which can be manipulated and assembled in magnetic fields. The M-gels can be used as building blocks for bottom-up tissue engineering to create 3D tissue constructs. For tissue engineering applications of M-gels, it is essential to study the release of encapsulated MNPs from the hydrogel polymer network and the effect of MNPs on hydrogel properties, including mechanical characteristics, porosity, swelling behavior, and cellular response (e.g., viability, growth). Therefore, we evaluated the release of MNPs from photocrosslinkable gelatin methacrylate hydrogels as the polymer network undergoes biodegradation using inductively coupled plasma atomic emission spectroscopy. MNP release correlated linearly with hydrogel biodegradation rate with correlation factors (Pearson product moment correlation coefficient) of 0.96 ± 0.03 and 0.99 ± 0.01 for MNP concentrations of 1% and 5%, respectively. We also evaluated the effect of MNPs on hydrogel mechanical properties, porosity, and swelling behavior, as well as cell viability and growth in MNP-encapsulating hydrogels. Fibroblasts encapsulated with MNPs in hydrogels remained viable (>80% at t = 144 h) and formed microtissue constructs in culture (t = 144 h). These results indicated that MNP-encapsulating hydrogels show promise as intelligent nanobiomaterials, with great potential to impact broad areas of bioengineering, including tissue engineering, regenerative medicine, and pharmaceutical applications.
Collapse
Affiliation(s)
- Feng Xu
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Fatih Inci
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Omer Mullick
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Umut Atakan Gurkan
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Yuree Sung
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Doga Kavaz
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Baoqiang Li
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
| | - Emir Baki Denkbas
- Nanotechnology and Nanomedicine Division, The Institute for Graduate Studies in Science and Engineering, Hacettepe University, 06800, Ankara, Turkey
| | - Utkan Demirci
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, United States
- Harvard—MIT Health Sciences and Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
17
|
Abstract
The gastrointestinal tract is home to some of the most deadly human diseases. Exacerbating the problem is the difficulty of accessing it for diagnosis or intervention and the concomitant patient discomfort. Flexible endoscopy has established itself as the method of choice and its diagnostic accuracy is high, but there remain technical limitations in modern scopes, and the procedure is poorly tolerated by patients, leading to low rates of compliance with screening guidelines. Although advancement in clinical endoscope design has been slow in recent years, a critical mass of enabling technologies is now paving the way for the next generation of gastrointestinal endoscopes. This review describes current endoscopes and provides an overview of innovative flexible scopes and wireless capsules that can enable painless endoscopy and/or enhanced diagnostic and therapeutic capabilities. We provide a perspective on the potential of these new technologies to address the limitations of current endoscopes in mass cancer screening and other contexts and thus to save many lives.
Collapse
Affiliation(s)
- Pietro Valdastri
- Science and Technology of Robotics in Medicine Laboratory, Vanderbilt University, Nashville, Tennessee 37235, USA.
| | | | | |
Collapse
|
18
|
Industry Update: The latest developments in therapeutic delivery. Ther Deliv 2011. [DOI: 10.4155/tde.11.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The present industry update covers the period 16 January–15 February 2011, with information sourced from company press releases, regulatory agencies and patent search engines. The announcement by Pfizer of almost 4000 job losses, the majority in R&D, reflects the current tough business environment of many of the big pharmaceutical companies. Whilst ongoing rationalization of the Pfizer business is necessary post-Wyeth, Pfizer clearly believe a structural change in their innovation model is required in order to enhance productivity and competitiveness, and counteract the financial implications of the expiration of key drug patents. The development and manufacturing agreement reached by Elan and Boehringer Ingelheim looks, on paper at least, to be a positive means of extracting synergies from their complementary business strengths. In terms of early-stage R&D, the designation of orphan drug status to CFAK-C4 has the potential to achieve real breakthroughs in the treatment of solid tumors and improve the outcomes of patients diagnosed with pancreatic cancer. The present issue also highlights the potential benefits associated with personalized medicines. The idea is not new since it is a key strategy employed in targeting therapeutics; however, greater understanding of disease etiology and improvements in diagnostic testing should provide more opportunity to treat the right patients with the right drug.
Collapse
|