Nexplanon: the new implant for long-term contraception. A comprehensive descriptive review

In Situ Forming, Enzyme-Responsive Peptoid-Peptide Hydrogels: An Advanced Long-Acting Injectable Drug Delivery System

Long-acting drug delivery systems are promising platforms to improve patient adherence to medication by delivering drugs over sustained periods and removing the need for patients to comply with oral regimens. This research paper provides a proof-of-concept for the development of a new optimized in situ forming injectable depot based on a tetrabenzylamine-tetraglycine-d-lysine-O-phospho-d-tyrosine peptoid-D-peptide formulation ((NPhe)4GGGGk(AZT)y(p)-OH). The chemical versatility of the peptoid-peptide motif allows low-molecular-weight drugs to be precisely and covalently conjugated. After subcutaneous injection, a hydrogel depot forms from the solubilized peptoid-peptide-drug formulation in response to phosphatase enzymes present within the skin space. This system is able to deliver clinically relevant concentrations of a model drug, the antiretroviral zidovudine (AZT), for 35 days in Sprague-Dawley rats. Oscillatory rheology demonstrated that hydrogel formation began within ∼30 s, an important characteristic of in situ systems for reducing initial drug bursts. Gel formation continued for up to ∼90 min. Small-angle neutron scattering data reveal narrow-radius fibers (∼0.78-1.8 nm) that closely fit formation via a flexible cylinder elliptical model. The inclusion of non-native peptoid monomers and D-variant amino acids confers protease resistance, enabling enhanced biostability to be demonstrated in vitro. Drug release proceeds via hydrolysis of an ester linkage under physiological conditions, releasing the drug in an unmodified form and further reducing the initial drug burst. Subcutaneous administration of (NPhe)4GGGGk(AZT)y(p)-OH to Sprague-Dawley rats resulted in zidovudine blood plasma concentrations within the 90% maximal inhibitory concentration (IC90) range (30-130 ng mL-1) for 35 days.

Use of etonogestrel subcutaneous implant in Sardinia, Italy: women's compliance and satisfaction

PURPOSE OF THE ARTICLE

The main aim of the study was to analyze the population of women who used etonogestrel implant, the reason that led them to this type of contraception, and the degree of compliance with it. Materials and methods: We carried out a retrospective study on women who had etonogestrel subcutaneous implant placed (n°47) over a 6-year period (2015-2021). We submitted the women a series of questions by telephone questionnaire (range 10-72 months after placements, mean 40 months) that investigated the comorbidities and side effects related to etonogestrel implant.

MATERIALS AND METHODS

We carried out a retrospective study on women who had etonogestrel subcutaneous implant placed (n°47) over a 6-year period (2015-2021). We submitted the women a series of questions by telephone questionnaire (range 10-72 months after placements, mean 40 months) that investigated the comorbidities and side effects related to etonogestrel implant.

RESULTS

The average age of placement of etonogestrel implant was 33.8 ± 3.45 years. As regards level of education, 16/47 (34%) of the women had a university degree, 21/47 (44%) had a high school diploma and 10/47 (21%) had a secondary school diploma. The 12/47 (25%) of the women were, at the time of the counselling, unemployed and only 8% did not use in the past contraceptive methods other than etonogestrel implant. The 92% of women choose etonogestrel implant because it offered safe, comfortable and long-lasting contraception. Among the main side effects evaluated, we reported spotting in 24 out of 47 (51%), headache in 4 out of 47 (8.5%). The 85% of the women recommended etonogestrel implant to their friends as a contraceptive method, with an approval rating for the implant, expressed a rating from 1 to 10 with the mean that was 7.79, the median 8.

CONCLUSIONS

Our results are of interest because they derive from a region of Italy in which the Long acting reversible contraception (LARC) is strongly underused. Etonogestrel implant was a safe and effective, long-acting, reversible hormonal contraception (LARC) and majority of women recommended the etonogestrel implant to their friends as a contraceptive method.

Etonogestrel promotes respiratory recovery in an in vivo rat model of central chemoreflex impairment

AIM

The central CO2 chemoreflex is a vital component of respiratory control networks, providing excitatory drive during resting conditions and challenges to blood gas homeostasis. The retrotrapezoid nucleus is a crucial hub for CO2 chemosensitivity; its ablation or inhibition attenuates CO2 chemoreflexes and diminishes restful breathing. Similar phenotypes characterize certain hypoventilation syndromes, suggesting underlying retrotrapezoid nucleus impairment in these disorders. Progesterone stimulates restful breathing and CO2 chemoreflexes. However, its mechanisms and sites of actions remain unknown and the experimental use of synthetic progestins in patients and animal models have been met with mixed respiratory outcomes.

METHODS

We investigated whether acute or chronic administration of the progestinic drug, etonogestrel, could rescue respiratory chemoreflexes following selective lesion of the retrotrapezoid nucleus with saporin toxin. Adult female Sprague Dawley rats were grouped based on lesion size determined by the number of surviving chemosensitive neurons, and ventilatory responses were measured by whole body plethysmography.

RESULTS

Ventilatory responses to hypercapnia (but not hypoxia) were compromised in a lesion-dependent manner. Chronic etonogestrel treatment improved CO2 chemosensitivity selectively in rats with moderate lesion, suggesting that a residual number of chemosensitive neurons are required for etonogestrel-induced CO2 chemoreflex recovery.

CONCLUSION

This study provides new evidence for the use of progestins as respiratory stimulants under conditions of central hypoventilation and provides a new testable model for assessing the mechanism of action of progestins in the respiratory network.

Long-Acting Reversible Etonogestrel Subdermal Implant in Adolescents

Several effective contraceptive options are available for use by adolescents, including the long-acting reversible subdermal implant and intrauterine devices, which provide a high level of convenience, privacy, and effectiveness for an adolescent. Knowledge of all the effective birth control methods is essential for the pediatrician to be able to provide effective contraceptive counseling for an adolescent. An approach to counseling using a reproductive justice framework, which allows the provider and adolescent patient to engage in shared decision-making, is described. This article focuses on the long-acting reversible etonogestrel (ENG) subdermal implant for adolescents. The ENG implant is labeled for preventing pregnancy by suppressing ovulation. The ENG implant may also have a role in ameliorating dysmenorrhea and heavy menstrual bleeding. Postlabeling studies indicate that the ENG implant is effective for up to 5 years, although the device's labeling states effectivenessup to 3 years. The main contraindication to using the ENG implant is pregnancy itself. Safe initiation of the ENG implant is described, including an approach to determine whether an adolescent is pregnant. The main adverse effect of the ENG implant is an unpredictable bleeding pattern that is most often ameliorated by use of nonsteroidal anti-inflammatory medications, as well as estrogen, if not contraindicated for the patient. Details of the insertion and removal procedures, including potential complications, are described to enable the pediatrician to provide effective anticipatory guidance for the adolescent.

An exploratory study on the possible association of serum etonogestrel concentrations with mood concerns and symptoms among contraceptive implant users

OBJECTIVE

To evaluate if inter-individual variability in serum etonogestrel (ENG) concentrations accounts for variability in mood-related side effects among ENG implant users.

STUDY DESIGN

Participants underwent a single-time blood draw for measurement of serum ENG concentrations using a liquid-chromatography mass-spectrometry assay, and completed a questionnaire at enrollment that retrospectively assessed mood-related side effects during the period of implant use. For a subset of participants, Patient Health Questionnaire-9 (PHQ-9) scores, obtained for other clinical purposes, were also compared. We used independent medians tests and linear regression to evaluate associations between mood symptoms and serum ENG concentrations as our primary outcome.

RESULTS

Among 900 enrolled participants, 34% (306/900) reported mood changes on the baseline questionnaire. Of these, 31 (3.4%) participants also had documented PHQ-9 scores. Serum ENG concentrations (median 126.9 pg/mL [range 39.4-695.1]) were not associated with reported mood changes on the questionnaire (p = 0.19) or on the PHQ-9 (β = 0.00, 95% CI -0.03, 0.03).

CONCLUSION

Pharmacokinetic variability does not explain the inter-individual variability in mood-related side effects among ENG implant users.

IMPLICATIONS

Mood-related side effects and altered mental health metrics are commonly reported by etonogestrel contraceptive implant users but demonstrate wide inter-individual variability. Individual differences in serum drug levels do not appear to account for this variability in mood-related side effects, and so future research should focus on novel personal factors.

Co-delivery of an HIV prophylactic and contraceptive using PGSU as a long-acting multipurpose prevention technology

OBJECTIVES

Poly(glycerol sebacate) urethane (PGSU) elastomers formulated with 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA), levonorgestrel (LNG), or a combination thereof can function as multipurpose prevention technology implants for prophylaxis against HIV and unintended pregnancies. For these public health challenges, long-acting drug delivery technologies may improve patient experience and adherence. Traditional polymers encounter challenges delivering multiple drugs with dissimilar physiochemical properties. PGSU offers an alternative option that successfully delivers hydrophilic EFdA alongside hydrophobic LNG.

METHODS

This article presents the formulation, design, and characterization of PGSU implants, highlighting the impact of API loading, dimensions, and individual- versus combination-loading on release rates.

RESULTS

Co-delivery of hydrophilic EFdA alongside hydrophobic LNG acted as a porogen to accelerate LNG release. Increasing the surface area of LNG-only implants increased LNG release. All EFdA-LNG, EFdA-only, and LNG-only formulated implants demonstrated low burst release and linear release kinetics over 245 or 122 days studied to date.

CONCLUSION

PGSU co-delivers two APIs for HIV prevention and contraception at therapeutically relevant concentrations in vitro from a single bioresorbable, elastomeric implant. A new long-acting polymer technology, PGSU demonstrates linear-release kinetics, dual delivery of APIs with disparate physiochemical properties, and biocompatibility through long-term subcutaneous implantation. PGSU can potentially meet the demands of complex MPT or fixed-dose combination products, where better solutions can serve and empower patients.

Recent advancements in single dose slow-release devices for prophylactic vaccines

Single dose slow-release vaccines herald a new era in vaccine administration. An ideal device for slow-release vaccine delivery would be minimally invasive and self-administered, making these approaches an attractive alternative for mass vaccination programs, particularly during the time of a pandemic. In this review article, we discuss the latest advances in this field, specifically for prophylactic vaccines able to prevent infectious diseases. Recent studies have found that slow-release vaccines elicit better immune responses and often do not require cold chain transportation and storage, thus drastically reducing the cost, streamlining distribution, and improving efficacy. This promise has attracted significant attention, especially when poor patient compliance of the standard multidose vaccine regimes is considered. Single dose slow-release vaccines are the next generation of vaccine tools that could overcome most of the shortcomings of present vaccination programs and be the next platform technology to combat future pandemics. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanomaterials and Implants Biology-Inspired Nanomaterials > Protein and Virus-Based Structures.

Translating diagnostics and drug delivery technologies to low-resource settings

Diagnostics and drug delivery technologies engineered for low-resource settings aim to meet their technical design specifications using strategies that are compatible with limited equipment, infrastructure, and operator training. Despite many preclinical successes, very few of these devices have been translated to the clinic. Here, we identify factors that contribute to the clinical success of diagnostics and drug delivery systems for low-resource settings, including the need to engage key stakeholders at an early stage, and provide recommendations for the clinical translation of future medical technologies.

Characteristics of Patients Requiring Surgical Removal of Subdermal Contraceptive Implants: A Case-Control Study

Purpose

Etonogestrel subdermal implants are a commonly used contraceptive device placed in the medial upper arm. Plastic and orthopedic surgeons may be consulted for difficult implant removals. We performed a case–control study comparing patients undergoing surgical and uncomplicated in-office removal at our institution.

Patients and Methods

We identified patients who underwent operative removal of implantable contraceptive devices by plastic or orthopedic surgeons at our institution from January 2014 to October 2019. Patients who underwent uncomplicated office removal during the same time were compared. Demographic and surgical variables were collected, and descriptive statistics were calculated. Univariate and multivariate logistic regression was performed with surgical versus outpatient removal as the outcome of interest.

Results

A total of 669 patients undergoing etonogestrel subdermal implant removals were identified during the five-year study period, of which thirteen patients required surgical removal (1.9%) and 326 were selected as uncomplicated removal comparisons. There were no significant differences in median (IQR) body mass index (BMI) (31.1 [28.2, 35.2] versus 29.3 [24.0, 35.1], p = 0.19), median (IQR) weight gain since device placement (5 [−0.6, 14.7] kilograms versus 1.6 [−1.2, 5.8] kilograms, p = 0.15), or length of time since device insertion (2.3 [0.8, 2.8] years versus 1.0 [0.4, 2.2] years, p = 0.17). Of those who needed surgical removal, the most common indication for implant removal was device expiration (n = 5, 38.5%). Devices placed by OBGYN attendings were less likely to require surgical removal (p = 0.02). Family medicine attendings were more likely to refer patients for surgical removal (p = 0.02). No significant findings were detected on univariate or multivariate regression. Among surgical removals, radiography was the most frequently used imaging modality. Implants were most frequently subdermal (n = 11, 84.6%) though intramuscular placement was also identified (n = 2, 15.4%). Only one patient had residual paresthesia along the length of the incision. No other complications were identified.

Conclusion

We did not identify risk factors associated with the difficult removal of etonogestrel subdermal implants. Practitioners should consult upper extremity surgeons if they encounter difficult removals.

Alternative Insertion Site of Nexplanon: Description of a Case Report and Systematic Review of the Literature

The etonogestrel (ENG) implant is among the most effective reversible contraceptives. It can be a good option for patients with different chronic diseases due to no clinically significant effects on lipid metabolism or liver function. Some limitations in the use of this type of device are represented by social and psychiatric disorders, where the easy accessibility of the device becomes a negative feature. In these patients several cases of self-removal or damage to the device have been reported. We report the successful insertion of the Nexplanon^® device into the scapular region in a young woman with a chronic psychiatric disorder. To verify the presence in the literature of other possible implantation sites, we performed a systematic review of the literature on Pubmed, Google scholar and Scopus from 2000 to 2021 using different combinations of the following terms: (Nexplanon), (contraceptive implant), (insertion). Two manuscripts with three cases were detected. Nexplanon^® was implanted in the upper back. In all cases, there were no complications during the insertions and the follow up demonstrated no side effects with contraceptive efficacy. Our report and review is a further confirmation that the scapular region can become a valid insertion site, maintaining good efficacy and safety of the subcutaneous device.

Etonogestrel contraceptive implant failure in a woman taking rifampin: a case report

Background

The etonogestrel subdermal implant is the most efficacious hormonal contraceptive currently available and provides 99.7% effective contraception. However, similar to other hormonal contraception, its effectiveness is compromised with the use of cytochrome P450 inducing drugs resulting in an unplanned pregnancy. Despite this risk, little is known about the outcome of concomitant use of rifampin and contraceptive implants.

Case presentation

A 24-year-old woman was provided with an etonogestrel implant in September 2018. In July 2020, she was started with rifampin based anti-tuberculosis for tuberculosis of the lymph nodes. In December 2020, she presented to the family planning clinic of St. Paul’s Hospital Millennium Medical college with a diagnosis of failed implant and second-trimester pregnancy at a gestational age of 19 weeks. The etonogestrel implant was removed and the patient was linked to antenatal care follow up.

Conclusion

Concomitant use of hepatic cytochrome P450 enzyme-inducing medications with certain hormonal contraceptives may reduce effectiveness resulting in unintended pregnancy. Women should be given detailed counseling about the potential for drug interactions and a multidisciplinary approach with consultation or referral to reproductive health specialists is crucial for optimal management of women who are at increased risk of contraceptive failure and unintended pregnancy.

Medical Applications of Porous Biomaterials: Features of Porosity and Tissue-Specific Implications for Biocompatibility

Porosity is an important material feature commonly employed in implants and tissue scaffolds. The presence of material voids permits the infiltration of cells, mechanical compliance, and outward diffusion of pharmaceutical agents. Various studies have confirmed that porosity indeed promotes favorable tissue responses, including minimal fibrous encapsulation during the foreign body reaction (FBR). However, increased biofilm formation and calcification is also described to arise due to biomaterial porosity. Additionally, the relevance of host responses like the FBR, infection, calcification, and thrombosis are dependent on tissue location and specific tissue microenvironment. In this review, the features of porous materials and the implications of porosity in the context of medical devices is discussed. Common methods to create porous materials are also discussed, as well as the parameters that are used to tune pore features. Responses toward porous biomaterials are also reviewed, including the various stages of the FBR, hemocompatibility, biofilm formation, and calcification. Finally, these host responses are considered in tissue specific locations including the subcutis, bone, cardiovascular system, brain, eye, and female reproductive tract. The effects of porosity across the various tissues of the body is highlighted and the need to consider the tissue context when engineering biomaterials is emphasized.

Etonogestrel Administration Reduces the Expression of PHOX2B and Its Target Genes in the Solitary Tract Nucleus

Heterozygous mutations of the transcription factor PHOX2B are responsible for Congenital Central Hypoventilation Syndrome, a neurological disorder characterized by inadequate respiratory response to hypercapnia and life-threatening hypoventilation during sleep. Although no cure is currently available, it was suggested that a potent progestin drug provides partial recovery of chemoreflex response. Previous in vitro data show a direct molecular link between progestins and PHOX2B expression. However, the mechanism through which these drugs ameliorate breathing in vivo remains unknown. Here, we investigated the effects of chronic administration of the potent progestin drug Etonogestrel (ETO) on respiratory function and transcriptional activity in adult female rats. We assessed respiratory function with whole-body plethysmography and measured genomic changes in brain regions important for respiratory control. Our results show that ETO reduced metabolic activity, leading to an enhanced chemoreflex response and concurrent increased breathing cycle variability at rest. Furthermore, ETO-treated brains showed reduced mRNA and protein expression of PHOX2B and its target genes selectively in the dorsal vagal complex, while other areas were unaffected. Histological analysis suggests that changes occurred in the solitary tract nucleus (NTS). Thus, we propose that the NTS, rich in both progesterone receptors and PHOX2B, is a good candidate for ETO-induced respiratory modulation.

Associations Between Income Status and Perceived Barriers to Using Long-Acting Reversible Contraception: An Exploratory Study

Introduction

Barriers to long-acting reversible contraception (LARC) use in the United States have been described in prior studies, but few have focused on women's income status. We explored associations between income status and perceived LARC barriers in a community-based sample of reproductive-aged women.

Methods

Non-pregnant, heterosexually active women aged 18 to 40 years completed a cross-sectional survey at a large community event in the Midwestern U.S. in 2018. Outcome measures were comprised of 26 survey items gauging perceived barriers to LARC use (e.g., access barriers, side effects). We estimated crude and age-adjusted prevalence ratios (PRs) for each outcome by participants' income status: low-income (≤ 200% of federal poverty guideline) versus higher income.

Results

Low-income women (n = 72) were significantly more likely than higher income women (n = 183) to endorse 11 of the 26 barriers to LARC use (PR range, 1.23–7.63). Cost of LARC was the most frequently identified access barrier and was more acute for low-income women (PR 1.57, 95% CI 1.17–2.11). After adjustment for age, most associations were attenuated. However, low-income women were still more likely to report concerns about LARC use due to family expectations or beliefs (aPR 3.69, 95% CI 1.15–11.8).

Conclusion

Low-income women perceive more barriers to LARC access and more negative perceptions about use. While these associations also correlate with age, they nonetheless reflect concerns that impact contraceptive equity. Efforts to increase LARC access should address these barriers and focus on concerns more common among low-income women regarding LARC use.

Recent progress in advanced biomaterials for long-acting reversible contraception

Unintended pregnancy is a global issue with serious ramifications for women, their families, and society, including abortion, infertility, and maternal death. Although existing contraceptive strategies have been widely used in people's lives, there have not been satisfactory feedbacks due to low contraceptive efficacy and related side effects (e.g., decreased sexuality, menstrual cycle disorder, and even lifelong infertility). In recent years, biomaterials-based long-acting reversible contraception has received increasing attention from the viewpoint of fundamental research and practical applications mainly owing to improved delivery routes and controlled drug delivery. This review summarizes recent progress in advanced biomaterials for long-acting reversible contraception via various delivery routes, including subcutaneous implant, transdermal patch, oral administration, vaginal ring, intrauterine device, fallopian tube occlusion, vas deferens contraception, and Intravenous administration. In addition, biomaterials, especially nanomaterials, still need to be improved and prospects for the future in contraception are mentioned.

Assessing the cost-effectiveness of contraceptive methods from a health provider perspective: case study of Kiambu County Hospital, Kenya

BACKGROUND

Kenya's contraceptive prevalence rate at 53% is low, with wide disparity among the 47 counties that make up the country (2-76%). Significant financial investment is required to maintain this level of contraceptive use and increase it to levels seen in more developed countries. This is in the context of a growing population, declining donor funding, limited fiscal space and competing health challenges. Studies have shown that long-term contraceptive methods are more cost-effective than short-term methods. However, it is unclear if this applies in Sub-Saharan Africa; with limited financial resources, lower social economic status among users, and publicly managed commodity supply chains, in vertical programs largely dependent on donor funding. This study assessed the cost-effectiveness of contraceptive methods used in Kenya.

METHODS

A cross-sectional study was undertaken in a county referral hospital in mid-2018. Purposive sampling of 5 family planning clinic providers and systematic sampling of 15 service delivery sessions per method was done. Questionnaire aided interviews were done to determine inputs required to provide services and direct observation to measure time taken to provide each method. Cost per method was determined using activity based costing, effectiveness via couple year protection conversion factors, and cost-effectiveness was expressed as cost per couple year protection.

RESULTS

The intra-uterine copper device was most cost-effective at 4.87 US dollars per couple year protection followed by the 2-Rod Implant at 6.36, the 1-Rod Implant at 9.50, DMPA at 23.68, while the combined oral contraceptive pills were least cost-effective at 38.60 US dollars per couple year protection. Long-term methods attracted a higher initial cost of service delivery when compared to short-term methods.

CONCLUSION

Long-term contraceptive methods are more cost-effective. As such, investing in long-term contraceptives would save costs despite higher initial cost of service delivery. It is recommended, therefore, that Sub-Saharan Africa countries allocate more domestic financial resources towards availability of contraceptive services, preferably with multi-year planning and budget commitment. The resources should be invested in a wide range of interventions shown to increase uptake of long-term methods, including reduction of cost barriers for the younger population, thereby increasing contraceptive prevalence rates.

Implantable system for chronotherapy

Diurnal variation in enzymes, hormones, and other biological mediators has long been recognized in mammalian physiology. Developments in pharmacobiology over the past few decades have shown that timing drug delivery can enhance drug efficacy. Here, we report the development of a battery-free, refillable, subcutaneous, and trocar-compatible implantable system that facilitates chronotherapy by enabling tight control over the timing of drug administration in response to external mechanical actuation. The external wearable system is coupled to a mobile app to facilitate control over dosing time. Using this system, we show the efficacy of bromocriptine on glycemic control in a diabetic rat model. We also demonstrate that antihypertensives can be delivered through this device, which could have clinical applications given the recognized diurnal variation of hypertension-related complications. We anticipate that implants capable of chronotherapy will have a substantial impact on our capacity to enhance treatment effectiveness for a broad range of chronic conditions.

Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance is effective, quick, and safe

Objectives

The aim of this study was to assess the feasibility, performance, and complications of a non-surgical, minimally-invasive procedure of deep contraceptive implant removal under continuous ultrasound guidance.

Methods

The ultrasound-guided procedure consisted of local anesthesia using lidocaine chlorhydrate 1% (10 mg/mL) with a 21-G needle, followed by hydrodissection using NaCl 0.9% (9 mg/mL) and implant extraction using a Hartmann grasping microforceps. The parameters studied were the implant localization, success and complication rates, pain throughout the intervention, volumes of lidocaïne and NaCl used, duration of the procedure, and size of the incision. Between November 2019 and January 2021, 45 patients were referred to the musculoskeletal radiology department for ultrasound-guided removal of a deep contraceptive implant and were all retrospectively included.

Results

All implants were successfully removed en bloc (100%). The mean incision size was 2.7 ± 0.5 mm. The mean duration of the extraction procedure was 7.7 ± 6.3 min. There were no major complications (infection, nerve, or vessel damage). As a minor complication, 21 patients (46.7%) reported a benign superficial skin ecchymosis at the puncture site, spontaneously regressing in less than 1 week. The procedure was very well-tolerated, with low pain rating throughout (1.0 ± 1.5/10 during implant extraction).

Conclusions

Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, effective, and safe. In the present cohort, all implants were successfully removed, whatever the location, with short procedural time, small incision size, low pain levels, and no significant complications. This procedure could become a gold standard in this indication.

Key Points

• Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, which led to a success rate of 100% whatever the location (even close to neurovascular structures), with only a small skin incision (2.7 ± 0.5 mm).

• The procedure was safe, quick, without any major complications, and very well tolerated in terms of pain.

• This minimally invasive ultrasound-guided procedure could become the future gold standard for the removal of deep contraceptive implants, as an alternative to surgical extraction, even for implants in difficult locations such as subfascial ones or those close to neurovascular structures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08263-4.

Vitamin D3-loaded electrospun cellulose acetate/polycaprolactone nanofibers: Characterization, in-vitro drug release and cytotoxicity studies

Vitamin D deficiency is now a global health problem; despite several drug delivery systems for carrying vitamin D due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D₃ is a strong incentive in the current study. Hence, an implantable drug delivery system (IDDS) was developed from the electrospun cellulose acetate (CA) and ε-polycaprolactone (PCL) nanofibrous membrane, in which the core of implants consists of vitamin D₃-loaded CA nanofiber (CAVD) and enclosed in a thin layer of the PCL membrane (CAVD/PCL). CA nanofibrous mat loaded with vitamin D₃ at the concentrations of 6, 12, and 20% (w/w) of vitamin D₃ were produced using electrospinning. The smooth and bead-free fibers with diameters ranged from 324 to 428 nm were obtained. The fiber diameters increased with an increase in vitamin D₃ content. The controlled drug release profile was observed over 30-days, which fit with the zero-order model (R² > 0.96) in the first stage. The mechanical properties of IDDS were improved. Young's modulus and tensile strength of CAVD/PCL (dry) were161 ± 14 and 13.07 ± 2.5 MPa, respectively. CA and PCL nanofibers are non-cytotoxic based on the results of the in-vitro cytotoxicity studies. This study can further broaden in-vivo study and provide a reference for developing a new IDDS to carry vitamin D₃ in the future.

Contraceptive subcutaneous device migration: what does an orthopaedic surgeon need to know? A case report and literature review

Subdermal contraceptive implant is approved in more than 60 countries and used by millions of women around the world. Although relatively safe in nature, their implantation and removal may be associated with potential complications, some of which may require surgical intervention. Two types of peripheral neurological complications are reported: complications related to compressive neuropathy caused by device decubitus and complications related to device improper removal. An healthy 35-year-old woman come to our attention for paresthesia from medial side of right elbow to fourth and fifth fingers. Tinel sign was positive on medial side of distal third of right arm, above the elbow, as well. Clinical history of patients revealed a subcutaneous placement of a etonogestrel implant 3 years before. Patients reported disappearing of tactile feeling of subcutaneous contraceptive implant since two months. At clinical examination, implant was not felt in its original subcutaneous place. X-rays control revealed its proximal and deep migration. Surgical exploration for subcutaneous contraceptive implant removal revealed it lying on the ulnar nerve. Patient referred immediate paresthesia disappearing after surgery. At 1 month follow up no motor or sensory alteration were evident. Removal of implants inserted too deeply must be carefully performed to prevent damages to nervous and vascular structures and it should be performed by operators who are very familiar with the anatomy of the arm. In case of chronic neuropathy caused by implant nerve compression only an appropriate patients information about rare but possible neuropathic symptoms related to device migration and a careful medical history collecting can avoid a mistaken diagnosis of canalicular syndrome.

Transgender Women's Concerns and Preferences on Potential Future Long-Acting Biomedical HIV Prevention Strategies: The Case of Injections and Implanted Medication Delivery Devices (IMDDs)

There are several long-acting biomedical HIV prevention products in the development pipeline, including injections and implanted medication delivery devices (IMDDs). It is critical to understand concerns and preferences on the use of these products in populations that shoulder a disproportionate burden of the HIV epidemic, such as transgender women. This will allow researchers and public health professionals to construct interventions tailored to the needs of these women to promote optimal use of these tools. In studies of other biomedical HIV prevention products (e.g., oral PrEP) it is clear that transgender women have unique concerns related to the use of these strategies. This may have an impact on this group's uptake and sustained use of longacting HIV prevention products. This study conducted four focus groups with N = 18 transgender women in New York City to understand their concerns and preferences on long-acting PrEP injections and IMDDs. Findings showed that participants were overwhelmingly positive about long-acting HIV prevention strategies, though they had some apprehensions. Overall, participants felt that injections and IMDDs could help address adherence challenges, and that transgender-specific needs should be addressed during clinical trials. Also, there were concerns related to injection or IMDD logistics, concerns about injections' or IMDDs' presence in the body, and familiarity with these products affected participants' opinions on them. Findings from this work can be used to inform protocols, measures, materials, and adherence interventions in future initiatives for transgender women using PrEP injections or IMDDs.

Development of a Biodegradable Subcutaneous Implant for Prolonged Drug Delivery Using 3D Printing

Implantable drug delivery devices offer many advantages over other routes of drug delivery. Most significantly, the delivery of lower doses of drug, thus, potentially reducing side-effects and improving patient compliance. Three dimensional (3D) printing is a flexible technique, which has been subject to increasing interest in the past few years, especially in the area of medical devices. The present work focussed on the use of 3D printing as a tool to manufacture implantable drug delivery devices to deliver a range of model compounds (methylene blue, ibuprofen sodium and ibuprofen acid) in two in vitro models. Five implant designs were produced, and the release rate varied, depending on the implant design and the drug properties. Additionally, a rate controlling membrane was produced, which further prolonged the release from the produced implants, signalling the potential use of these devices for chronic conditions.

Simple minimally-invasive automatic antidote delivery device (A2D2) towards closed-loop reversal of opioid overdose

With approximately 48,000 attributed deaths in 2017, the opioid overdose is now the leading cause of death amongst Americans under the age of 50. The overdose process can be interrupted by the administration of naloxone, a safe and effective opiate antagonist that can reverse the effects of overdose and minimizing the delay in administering the antidote is critical in preventing permanent damage to patients. A closed-loop implantable drug delivery system is an ideal solution to minimize the response time, however, they often feature complex designs that are expensive to fabricate and require a more invasive surgical implantation. Here we propose a simple, low-cost, minimally-invasive automatic antidote delivery device (A2D2) that can administer a large dose of naloxone upon detection of overdose-induced respiratory failure. The subcutaneously placed device can be activated using an externally applied time varying magnetic field from a wearable device. Using a custom magnetic field generator, we were able to release the drug within 10 s. Our bench-top evaluation showed that A2D2 can release 1.9 mg of powdered drug within 60 s and up to 8.8 mg in 600 s. We also performed in vivo evaluation to demonstrate rapid drug releasing capability in the subcutaneous space of mice. However, we saw a small amount of leakage (1.75% of payload) over the course of 1000 h of simulated implantation. Thus, additional research is needed to verify the long term stability of our device and to demonstrate the closed-loop release mechanism to revive overdosed animals. Nevertheless, our preliminary results show the potential of using a simple, low-cost, subcutaneous device for emergency drug delivery application.

Implantable Polymeric Drug Delivery Devices: Classification, Manufacture, Materials, and Clinical Applications

The oral route is a popular and convenient means of drug delivery. However, despite its advantages, it also has challenges. Many drugs are not suitable for oral delivery due to: first pass metabolism; less than ideal properties; and side-effects of treatment. Additionally, oral delivery relies heavily on patient compliance. Implantable drug delivery devices are an alternative system that can achieve effective delivery with lower drug concentrations, and as a result, minimise side-effects whilst increasing patient compliance. This article gives an overview of classification of these drug delivery devices; the mechanism of drug release; the materials used for manufacture; the various methods of manufacture; and examples of clinical applications of implantable drug delivery devices.

Long acting systemic HIV pre-exposure prophylaxis: an examination of the field

Oral pre-exposure prophylaxis for the prevention of HIV-1 transmission (HIV PrEP) has been widely successful as demonstrated by a number of clinical trials. However, studies have also demonstrated the need for patients to tightly adhere to oral dosing regimens in order to maintain protective plasma and tissue concentrations. This is especially true for women, who experience less forgiveness from dose skipping than men in clinical trials of HIV PrEP. There is increasing interest in long-acting (LA), user-independent forms of HIV PrEP that could overcome this adherence challenge. These technologies have taken multiple forms including LA injectables and implantables. Phase III efficacy trials are ongoing for a LA injectable candidate for HIV PrEP. This review will focus on the design considerations for both LA injectable and implantable platforms for HIV PrEP. Additionally, we have summarized the existing LA technologies currently in clinical and pre-clinical studies for HIV PrEP as well as other technologies that have been applied to HIV PrEP and contraceptives. Our discussion will focus on the potential application of these technologies in low resource areas, and their use in global women's health.

Influence of age on tolerability, safety and effectiveness of subdermal contraceptive implants

The use of long-acting contraceptive methods is on the rise. The aim of this study was to describe the main variables (effectiveness, tolerability, menstrual bleeding) associated with the use of subdermal contraceptive implants and to investigate the influence of age on these variables. This was a descriptive, retrospective, observational study of 221 cases of contraceptive implants inserted at a Spanish hospital between 2006 and 2015. The mean age of implant users was 31.2 ± 7.5 years. Effectiveness was 100% and good tolerability was recorded for 86.5%. Infrequent bleeding was the most common bleeding pattern, followed by amenorrhoea. Of the 221 implants inserted, 47.5% were removed. The main reasons were expiration (54.3%) and discomfort due to bleeding alterations and other adverse effects (25.7%). Nulliparity and weight gain were significantly associated with an increased probability of implant removal. This study shows that implants were highly effective, safe and well-tolerated in our population. The age of users had no influence on any of the study variables analysed. Impact Statement What is already known on this subject? Subdermal contraceptive implants are long-acting reversible contraceptives which are both safe and effective. What do the results of this study add? The age of users had no influence on any of the study variables analysed. Nulliparity and weight gain were significantly associated with an increased probability of implant removal. What are the implications of these findings for clinical practice and/or further research? Subdermal contraceptive implants were a safe and effective long-acting progestin contraceptive method for women from all age groups in our series because no significant age-related differences were observed for the tolerability, vaginal bleeding patterns, the effectiveness, the adverse effects or any other variables.

Factors associated with removal difficulties of etonogestrel-containing contraceptive implants (Nexplanon®)

OBJECTIVES

Nexplanon^®'s new applicator system was designed to limit deep implant placements, known to lead to difficult removals. However, removal difficulties still exist and induce specific and potentially severe complications. Our objective was to identify risk factors associated with difficult removals.

STUDY DESIGN

A retrospective single-center study was performed from January 2015 to December 2016. Participants were divided into two groups depending on whether implant was removed during a standard ("standard removal" group) or difficult consultation ("difficult removal" group) after an initial failed removal attempt.

RESULTS

The difficult and standard removal groups comprised 63 and 660 women, respectively. In a univariate analysis, significant intergroup differences were found for weight gain (3.7 ± 7.3 kg in the difficult removal group vs. 1.3 ± 5.1 in the standard removal group), proportion of placements performed in private practice (66.7% vs. 19.8%, respectively), and duration of Nexplanon^® placement (29.4 ± 11.3 months versus 26 ± 13.6, respectively). We also reported more frequent sub-brachial fascia placements when Nexplanon^® was implanted by a private practitioner (7.5% cases versus 0.4% in hospital implantations, p < 0.001). In a stepwise binary logistic regression analysis, placement by a private practitioner, weight gain >1 kg since placement, and duration of implant placement >25 months were confirmed as independent risk factors for removal difficulties (respective risk ratios 7.63 [95% IC 4.35-13.33], 2.10 [1.18-3.70], and 1.91 [1.06-3.44], p < 0.05).

CONCLUSIONS

Awareness of these three simple parameters might help physicians to identify "at risk-patients", and suggest a specific consultation before risking a potentially hazardous removal (with its associated, specific morbidity). Our results also emphasize importance of training in implant insertion.

Axillary migration of Nexplanon®: Case report

A 19-year-old patient presented to the clinic, and we inserted a single rod subdermal etonogestrel implant (Nexplanon ®), which subsequently migrated to the ipsilateral axilla. Distant Nexplanon® migration is a rare serious complication that should be considered when a device is nonpalpable. Management options are discussed.

Monthly Periods--Are They Necessary?

Menstrual suppression--the use of hormones to delay or eliminate menses--is often used in adolescents to manage conditions associated with the menstrual cycle and to accommodate lifestyle preferences. Reducing the frequency of menstrual bleeding does not cause any known physiologic harm and has potential short-term and long-term advantages. Different methods used for menstrual suppression, however, have associated risks and side effects that need to be weighed against the benefits of controlling menses. This article reviews the advantages and disadvantages of menstrual suppression and the different methods available for adolescents.

Developments in contraception

INTRODUCTION

Although the contraceptive options for women have expanded considerably in the last decade, these methods are often not being offered to women as choices because clinicians are not well informed, limiting the ability of women to control their fertility.

AREAS COVERED

Areas covered include the use of oestradiol instead of ethinyl oestradiol and improved progestogens utilised in hormonal contraceptives, and new delivery systems have enabled the development of long-acting methods, which require less action on the part of the user, and thereby, reduce failure rates. Effective emergency contraceptive methods have become more readily available over the counter. However, male contraception, despite much research, still remains elusive.

EXPERT OPINION

This manuscript will provide an assessment of recent advances and controversies in contraception and make suggestions about improved availability.

Long-acting reversible contraception

Although short-acting reversible hormonal contraceptives, such as oral contraceptives and the contraceptive patch and vaginal ring, remain the most commonly used contraceptive methods in the United States, they are also associated with the highest failure rates. Long-acting reversible contraception (LARC) methods, such as intrauterine devices and contraceptive implants, offer high continuation rates and very low failure rates, and are safe for use in most women. The provision of LARC methods to adolescent, young adult and nulliparous women is a relatively new concept that offers an innovative option for these populations.

History of oral contraceptive drugs and their use worldwide

The first hormonal pill, called Enovid(®), was approved by the Federal Drug Administration (FDA) in May 1960. It contained mestranol and norethisterone. Over the years, oral contraceptives have evolved through gradual lowering of ethinyl estradiol (EE) content, introduction of 17β estradiol, and many different progestins. The standard regimen allows for 21 days of pill containing steroids and a pill-free interval of 7 days. Recently, continuous or extended regimens have been approved. In order to improve compliance, alternative routes of combined oral contraceptive (COC) administration have been developed such as vaginal or transdermal routes. In 2009, according to the United Nations, the mean global percentage using contraception in women who are married or in union was 62.7%. COC represented 8.8% of contraceptive prevalence, reaching 15.4% in more developed countries. More than 100 million women worldwide use COCs. However, each year, many unintended pregnancies occur, indicating that contraception still needs to be promoted.