Next-generation surgicalmeshes for drug delivery and tissue engineering applications:materials,design and emerging manufacturing technologies

Surgical meshes have been employed in the management of a variety of pathological conditions including hernia,pelvic floor dysfunctions,periodontal guided bone regeneration,wound healing and more recently for breast plastic surgery after mastectomy.These common pathologies affect a wide portion of the worldwide population;therefore,an effective and enhanced treatment is crucial to ameliorate patients’living conditions both from medical and aesthetic points of view.At present,non-absorbable synthetic polymers are the most widely used class of biomaterials for the manufacturing of mesh implants for hernia,pelvic floor dysfunctions and guided bone regeneration,with polypropylene and poly tetrafluoroethylene being the most common.Biological prostheses,such as surgical grafts,have been employed mainly for breast plastic surgery and wound healing applications.Despite the advantages of mesh implants to the treatment of these conditions,there are still many drawbacks,mainly related to the arising of a huge number of post-operative complications,among which infections are the most common.Developing a mesh that could appropriately integrate with the native tissue,promote its healing and constructive remodelling,is the key aim of ongoing research in the area of surgical mesh implants.To this end,the adoption of new biomaterials including absorbable and natural polymers,the use of drugs and advanced manufacturing technologies,such as 3D printing and electrospinning,are under investigation to address the previously mentioned challenges and improve the outcomes of future clinical practice.The aim of this work is to review the key advantages and disadvantages related to the use of surgical meshes,the main issues characterizing each clinical procedure and the future directions in terms of both novel manufacturing technologies and latest regulatory considerations.

A 14-year multi-institutional collaborative study of Chinese pelvic floor surgical procedures related to pelvic organ prolapse

Background:It has been a global trend that increasing complications related to pelvic floor surgeries have been reported over time.The current study aimed to outline the development of Chinese pelvic floor surgeries related to pelvic organ prolapse(POP)over the past 14 years and investigate the potential influence of enhanced monitoring conducted by the Chinese Association of Urogynecology since 2011.Methods:A total of 44,594 women with POP who underwent pelvic floor surgeries between October 1,2004 and September 30,2018 were included from 22 tertiary academic medical centers.The data were reported voluntarily and obtained from a database.We compared the proportion of each procedure in the 7 years before and 7 years after September 30,2011.The data were analyzed by performing Z test(one-sided).Results:The number of different procedures during October 1,2011-September 30,2018 was more than twice that during October 1,2004-September 30,2011.Regarding pelvic floor surgeries related to POP,the rate of synthetic mesh procedures increased from 38.1%(5298/13,906)during October 1,2004-September 30,2011 to 46.0%(14,107/30,688)during October 1,2011-September 30,2018,whereas the rate of non-mesh procedures decreased from 61.9%(8608/13,906)to 54.0%(16,581/30,688)(Z=15.53,P<0.001).Regarding synthetic mesh surgeries related to POP,the rates of transvaginal placement of surgical mesh(TVM)procedures decreased from 94.1%(4983/5298)to 82.2%(11,603/14,107)(Z=20.79,P<0.001),but the rate of laparoscopic sacrocolpopexy(LSC)procedures increased from 5.9%(315/5298)to 17.8%(2504/14,107).Conclusions:The rate of synthetic mesh procedures increased while that of non-mesh procedures decreased significantly.The rate of TVM procedures decreased while the rate of LSC procedures increased significantly.Trial registration number:NCT03620565,https://register.clinicaltrials.gov.

Accelerated neutral atom beam(ANAB)and gas clustered ion beam(GCIB)treatment of implantable device polymers leads to decreased bacterial attachment in vitro and decreased inflammation in vivo

Infections at the placement site of biomaterial-based devices and subsequent scar formation results in morbidity,which may require revision surgery.Biomaterials intended for permanent implantation in the body need to be biologically inert to avoid excessive foreign body response and to reduce bacterial attachment.In this study,we show that polymeric materials commonly used in medical devices,including polyetheretherketone(PEEK)and polypropylene,treated by gas cluster ion beam(GCIB)or by accelerated neutral atom beam(ANAB)result in a nanoscale-modified surface topography that changes the ability of extracellular proteins to bind.This leads to decreased bacterial attachment and an attenuated inflammatory response using both in vitro and in vivo assays.Differential adsorption of extracellular proteins to the polymeric surface improved the competitive attachment of osteoblasts over bacteria,without resorting to growth factor of antibiotic use.